Cataract is a condition where the natural lens in the eye becomes progressively cloudy, impacting your vision and making it difficult for you to go about performing your daily activities.

Most forms of cataract develop in adult life, causing the lens to harden and become cloudy as you age. 

Although most cataracts are age-related, there are other types which include:

• Congenital (present at birth), 

• Drug-induced (steroids), and 

• Traumatic (injury to the eye). 

Cataract is also more common in people who have certain diseases such as diabetes, which tend to occur at an earlier age than those without the disease.

While cataract cannot be prevented, it can be treated by a surgical procedure commonly known as phacoemulsification, where the cloudy cataract lens is removed and replaced with an artificial lens implant.

To learn more about cataract surgery (phacoemulsification), watch this video!

If the amount of cataract is little and does not disturb your vision or your daily activities (e.g. driving or reading), it can be left alone. Eyeglasses may help at this stage to allow you to see better. 

If using eyeglasses does not help, and the cataract interferes your vision, your eye doctor may suggest doing a cataract surgery.

In this "Ask The Specialist", don't miss the chance to ask Dr Lim any question you may have about cataract - a common condition that affects over 80 per cent of people in Singapore, aged 60 and above.

About Dr Jane Lim

Dr Jane Lim is a Consultant with the Cataract & Comprehensive Ophthalmology at the Singapore National Eye Centre (SNEC). She obtained her Medical Degree from the National University of Singapore with a Bachelor of Medicine and Bachelor of Surgery (MBBS). 

In medical school, she was elected and served as an executive committee member of the National University of Singapore Medical Society. She was awarded the MOH training award to pursue Ophthalmology residency training in Singapore and successfully completed it with the Singapore National Eye Centre (SNEC). 

She subsequently obtained her Masters of Medicine (Ophthalmology), and attained fellowships with The Royal College of Ophthalmologists, and the Academy of Medicine Singapore.

Ref: H24

Questions and answers on cataract

1. Question by Jasmine

Dear Dr Lim,

I was told I have both cataract n glaucoma in both eyes.  I am 62 years old. I would like to seek some clarifications:

a) Can glaucoma be treated in conjunction with cataract op?

b) Will the glaucoma recur after treatment?

c) What sort of surgery is done for glaucoma?

Thank you.

Answer by Dr Lim

Dear Jasmine,

Glaucoma surgery can be done in conjunction with cataract operation. Glaucoma can still progress despite treatment. Regarding more details, it is best if you can discuss with your glaucoma specialist which treatment or surgery would be most suitable for you, and if you are suitable to do a combined glaucoma-cataract surgery.

2. Question by Choo Pheck

Hi Dr,

I have been diagnosed with Cataract in 2021.

The eye specialist said my cataract will take 10 years to be ripe and then can do the cataract removal.

But I have also heard from other eye specialists that there is no need for cataract to be ripe.

So, which is which? Thank you for your advice.

Answer by Dr Lim

Dear Choo Pheck,

While there may be differences in opinion between doctors regarding the optimal timing of cataract surgery, in general the need and timing of surgery depends on the patient’s visual requirements. For example, cataract surgery would be recommended when it starts to affect your daily living e.g. navigating, driving, cooking, watching tv. 

3. Question by TJ Lim

Hi Dr, can cataract recur after surgery?

Answer by Dr Lim

Dear TJ,

It is not possible for a cataract to recur. During cataract surgery, your cataract is removed and an artificial lens is placed into your eye‚ within its natural bag.  The new lens implant is permanent and will not need regular replacement.

However, with time, there may be cells remaining after cataract surgery that may grow over the back surface of the bag (capsule) holding the lens, causing the capsule to become cloudy. This can cause blurring of vision and is called "posterior capsular opacification". A laser procedure called a YAG capsulotomy can be used to make a small opening in the clouded capsule to provide a clear path through which light can pass.

4. Question by Marc Toh

Dear Dr Jane Lim,

I am 68 years old and wish to ask about the 1st and other signs of cataract. How are cataract treated and prevented?

Answer by Dr Lim

Dear Marc,

The most common symptoms of a cataract are: Gradual cloudy or blurry vision, poorer night vision, colours seem faded, glares and halos, and frequent prescription changes in your eyeglasses or contact lenses (cataract may cause the refractive error to keep changing). Very rarely, a very dense cataract can cause high pressure in the eye resulting in acute eye pain, redness, and blurring of vision. If you have any of these symptoms, you may consider consulting an ophthalmologist for further advice.

The only effective treatment for cataract is surgery, where the cloudy cataract lens is removed and then replaced with an artificial lens implant. The most common cause of cataract is aging. There is no known method of preventing cataracts from developing. Cataracts cannot be cured with medications.

Cataract can also occur at a younger age if you have poorly controlled diabetes, take certain types of medication such as steroids, are born with it (congenital), or experienced previous trauma to the eye.

You may reduce your risk of developing cataracts by:

• Protecting your eyes from ultra-violet (UV) light by wearing sunglasses

• Maintaining a healthy lifestyle and diet

• Treating diseases such as diabetes

• Not smoking

• Refrain from excessive rubbing or trauma to the eyes.

5. Question by Joey

Dear Doctor, 

Both my parents have cataract. My father went for one of his eyes cataract surgery 1 and a half years back. After it was done, he was allowed to go home and rest. But he's couldn't as he mentioned he was dizzy, headache and he couldn't even sleep. He was afraid even after two hours, he was supposed to take off his eye cover. After he removed the eye cover, he couldn't see and he mentioned he could only see in a very blur vision and it caused him to be very dizzy.

Now, despite one of his eyes recovered, another side of his eyes is getting the cataract as well but he don't dare to do it again as he has the phobia of getting the side effects he had previously. 

And now, my mother also having two eyes cataracts and is waiting for my father to go for surgery so as they can do it together.

Can I ask you, will the other side of his eyes get worse if he doesn't wish to do the surgery again? I really have no other options.

Looking forward to hearing your advice.

Answer by Dr Lim

Dear Joey,

I am sorry to hear about your father’s previous unpleasant surgical experience. It may be related to the sedation that was given to relief pain during the surgery.

In most cases, there is no harm in delaying cataract surgery, especially if one’s vision has not yet been affected. As a cataract matures with time, it hardens and leads to more cloudy vision, and can also be more difficult to remove during the surgery. As such, this can increase the risk of surgical complications. 

Very rarely, progression of the cataract can lead to inflammation and high pressure inside the eye which can be an emergency. I would advise to have a good discussion with your ophthalmologist together with your father to address any of his fears.

6. Question by Kim

Dear Dr,

I have done a lasik surgery on both of my eyes to correct my severe short sightedness more than ten eyes ago. Am I still suitable to do a cataract surgery? Thank you for the advice.

Answer by Dr Lim

Dear Kim,

LASIK surgery is not a contraindication for cataract surgery. You may proceed with cataract operation should it be deemed necessary. 

However, patients who have had previous refractive surgery may have less accurate intraocular lens implant calculation outcomes, and may not be suitable for certain lenses like multifocals. 

Do inform your ophthalmologist that you have had previous LASIK surgery before, and it would be best if you could obtain your previous medical records regarding the LASIK surgery.

This is required for more accurate measurement of your new lens implant for the cataract surgery in the future.

7. Question by Edward

Dear Dr Jane Lim,

I discovered I had some cataract issue 2 years ago with a “White Fogging” vision.

I have fixed an Eye Check appointment to be scheduled on 2nd April. This is a long wait for at least 6 months.

My vision is impaired in the last few months as I realised I could not see as clearly as I could.

My concerns and questions are:

a) There are a number of Cataract Doctor specialists, how could I choose the right Doctor who can do a good Cataract removal and Lens implant job? Any Doctor to recommend and how soon could I go for my First Cataract treatment and costs involve?

b) Could I seek the treatment at National Eye Centre? How to transfer my appointment?

c) I am concerned with the Doctor skills, experience and the Lens which I need to select to get me the best vision (both Far and near) what is your recommendation?

I have light short sighted vision of about 125 to 150 degrees, what kind of Lens should I choose? Thank you for your kind efforts.

Answer by Dr Lim

Dear Edward,

Unfortunately, the scope of this forum does not allow me to comment fully on your queries. I am unable to recommend you a doctor for cataract surgery in my current capacity. 

Most hospitals should include the profile of all of their active eye specialists for your reference on their website, and would indicate their level of seniority. The cost of a cataract operation depends on the choice of lenses, eligibility for government subsidies as well as insurance coverage. 

The type of lenses most suitable for you would be best assessed during an in-person consult with an ophthalmologist. You may also refer to another question that was answered about the different types of lenses. If you require more information, please schedule a visit with your ophthalmologist to find out more. 

You may refer to the SNEC website’s contact numbers (here) to find out how to connect with the appointment line.

8. Question by LK

Dear Dr Low,

a) Are there food we can take to slow down deterioration? 

b) Is there any relationship between cataract and floaters?

Thank you.

Answer by Dr Lim

Dear LK,

Cataracts and floaters arise from two completely different areas of the eye. They are not related. Cataract is a condition when the natural lens in your eye becomes progressively cloudy. Floaters are caused by degeneration of the vitreous gel in our eye that forms tiny clumps of gel or cells that cast a shadow on the retina.

There are no proven foods to slow down progression of cataracts. However, having a healthy diet such as taking fruits rich in vitamin C, vegetables, and reducing alcohol intake, will help.

9. Question by Chee Keong

Hi Dr Jane Lim.

I am 65 now & had LASIK for myopia correction in 2004.

I have been attending doctor consultations on my cataract progression past 3 over years.

The outcomes of the cataract for both eyes are still mild stage. But I feel my vision isn’t as good as before and often have to wear distance glasses.

I don’t feel comfortable wearing glasses since my LASIK in 2004 & had enjoyed my daily activities fully until recently.

Could I proceed to seek private eye consultant for elective cataract surgery despite my present mild cataract growth?

Appreciate that you could advise.

Answer by Dr Lim

Dear Chee Keong,

Generally it is advisable to do cataract operation only when cataract is visually significant e.g. if it is affecting your vision in your daily activities, due to the risks involved. 

Cataract surgery always carries a small risk of permanent, serious loss of vision, and should therefore be done when the benefits of surgery outweigh the potential surgical risks. 

Your need to wear distance glasses may also be attributed to regression of LASIK, rather than cataract progression. It is best to seek your ophthalmologist’s opinion for careful consideration.

10. Question by Eileen

Dear Dr Jane,

Can I wash my hair and face after cataract surgery? How soon can I start to wash my hair and face after cataract surgery? One day?

What methods can I use to wash my hair and face while recovering from cataract surgery without infection from the soap water entering my eyes? Any hacks to use? Thank you.

Answer by Dr Lim

Dear Eileen,

It is generally advised to prevent non-sterile water (that includes tap water or water from shower heads) from entering your eye for at least one month from the day of surgery, and to refrain from washing your hair until 2 days after the surgery to lower your risk of infection.

You may wash your face using a clean towel, and avoid splashing of water directly on it.

You may wash your hair by tilting your head backwards or go to a hair salon for assistance.

Be sure to keep your eyes closed and avoid getting any water or shampoo in your eye.

11. Question by Mr Koh

Dear Dr Jane,

What are your thoughts on early treatment of cataracts, or is more advisable to wait for the cataract to "ripen" before treatment?

May I know what is the lifespan of the artificial lens implant? Thank you!

Answer by Dr Lim

Dear Mr Koh,

While there may be differences in opinion between doctors regarding the optimal timing of cataract surgery, in general the need and timing of surgery depends on the patient’s visual requirements. For example, cataract surgery would be recommend when it starts to affect your daily living e.g. navigating, driving, cooking, watching tv. The assessment of whether cataract surgery would be beneficial (relative to the potential surgical risks) would also be surgeon-dependent, and would need to be discussed with your ophthalmologist.

The artificial lens implant is permanent and is made to last a life-time.

12. Question by Alex

Dear Dr. Jane,

Can Cataract happen even if I lead a normal lifestyle of wearing spectacles daily?

Recently I found out my right eye was difficult to open wide to focus object, I have used "Blink Tear" Eyes Drop daily, but the symptom still there.

I just consulted an Optician prescription to change my spectacle recently, so it seems unlikely because of my eye degree increase slightly.

May I know I still have to go for surgery to remove the white spot Cataract in my right eye?

My eye appointment is scheduled in Sept. Thank you.

Answer by Dr Lim

Dear Alex,

Wearing spectacles does not prevent cataract formation because cataract is due to clouding of the natural lens in our eye. Spectacles serve only to correct refractive error, not cataract formation.

I would advise you to see an ophthalmologist to assess your other symptoms in detail.

13. Question by Michael

Hi Dr,

I had cataract done 20 years ago. Now my left eye is a bit blurred. Do I have to do some operation to correct it or put on spectacles?

Answer by Dr Lim

Dear Michael,

It is hard to comment what are the causes of blurring of vision in your left eye from your description alone. 

The most common reason for blurring of vision after cataract surgery is a condition called Posterior Capsular Opacification, which can occur months or years after cataract surgery. This can happen in up to 20% of patients after cataract surgery. 

It is a result of cells forming a membrane along the back surface of the bag (lens capsule) that holds your artificial lens. It is normally treated successfully with a one-off minor laser procedure called a YAG laser capsulotomy. 

There may also be other causes of blurring of vision such as glaucoma, macular degeneration, or corneal edema.

I would recommend you to consult an ophthalmologist to determine the cause and subsequent treatment.

14. Question by Soon Lee

Hello Dr Lim,

I am 65-years old and was told of an early onset of cataract in my eyes.

My question is, can I perform phacoemulsification at this early stage or should I wait till it gets unbearable? My reason for doing it early is that I can enjoy good vision from now on instead of when I am closer to the grave. Thank you.

Answer by Dr Lim

Dear Soon Lee,

In general, the need and timing of doing cataract surgery would depend on your individual visual requirements. For example, cataract surgery would be recommended when it starts to affect your daily living e.g. navigating, driving, cooking, watching tv. 

Do keep in mind that cataract surgery carries a very small risk of permanent, serious loss of vision, and should therefore be done when the benefits of surgery outweigh the potential surgical risks. 

Do see an ophthalmologist to discuss further your need and considerations of the surgery based on your current eye condition.

14. Question by Rudin

Hi Dr,

Can I request for early Cataract surgery to correct my worsening presbyopia conditions?

What is the eligibility condition for such request?

What are the potential risks & conditions post-surgery?

Thank you for your advice.

Answer by Dr Lim

Dear Rudin,

Refractive lens exchange (which is cataract surgery performed mainly to reduce the need for glasses rather than to remove a cloudy lens) is an option to correct presbyopia (the loss of one’s eyes’ ability to see things up close). Cataract surgery involves replacing the natural lens with an artificial lens implant (intraocular lens (IOL)). The focusing power of the intraocular lens can be chosen to reduce dependence on glasses after surgery.

There are two main types of intraocular lenses:

1. Monofocal IOLs – which aim to reduce spectacle dependence for one distance, usually for distant/far vision. Glasses are then required for reading and near work.

2. Multifocal IOLs which can reduce spectacle dependence for a wider range of distances: distance, intermediate (computer screens) and near (reading) vision.

If you wish to reduce presbyopia (ie. To read without glasses) through cataract surgery, there are two approaches:

1. Using Monofocal IOLs -  Aim for clearer distance vision in one eye, and clearer vision at arms’ length in the other eye. With both eyes open, this allows you to combine both eyes’ range of focus, improving vision from distant objects to intermediate (computer screens). This is called a monovision strategy. However, you would normally still need glasses for certain activities like reading fine print, 3D vision (ball games), or driving. That being said, near vision is at least partly restored and gives you more convenience to perform most activities without glasses. It also spares you from the side effects of multifocal IOLs.

2. Using Multifocal IOLs – allows you to reduce spectacle dependence for a greater range of vision (Distant, intermediate, and near). However, they commonly have visual side effects such as halos around lights, blurring or ghosting, some light-scatter, and decreased contrast sensitivity (visual quality) compared to monofocal IOLs. Not everyone is suitable for multifocal IOLs as optimal eye health is important to benefit from this lens.

Your surgeon will need to assess your eye condition to determine if you are suitable for refractive lens exchange first, and will discuss which IOL type is the best option for you based on your test results and eye health findings.

However, do keep in mind that with all forms of eye surgery, problems can occur during the operation or afterwards in the healing period, and can result in permanent serious loss of vision. Risks of cataract surgery include endophthalmitis and blindness (1 in 1000), posterior capsule rupture, bleeding, retinal detachment, corneal swelling, retinal swelling, and droopy eyelids. Additional surgery may be required to correct a complication from the initial surgery.

Deciding to do refractive lens exchange would also be surgeon-dependent and would depend on your surgeon’s assessment if the benefits from the surgery outweighs the potential surgical risks based on your current eye condition.

15. Question by Delia

Dear Doctor Lim,

I have a cataract done on one eye as the other eye vision can be corrected with glasses.

However, my vision is still no good with a pair of progressive lenses.

Is the imbalance in terms of cataract done on one eye only causes the not so clear vision or could it be due to my progressive glasses? I look forward for your reply.

Answer by Dr Lim

Dear Delia,

Possible causes of your persistent blurring of vision despite a pair of progressive lenses could include:

1. Your glasses’ degree may not be accurate

2. The fellow eye has developed a cataract hence causing cloudy vision

3. The eye with cataract surgery done could have developed posterior capsule opacification, which can occur months or years after cataract surgery. This can happen in up to 20% of patients after cataract surgery. It is a result of cells forming a membrane along the back surface of the bag (lens capsule) that holds your artificial lens. It is normally treated successfully with a one-off minor laser procedure called a YAG laser capsulotomy.

4. Other causes of blurring of vision that would need to evaluated by an ophthalmologist.

The “imbalance” you’re referring to, when one eye has had cataract done first, is unlikely to be the cause of your blur vision. It may cause some colour perception imbalance between both eyes, but should not cause vision to be blurred if no new problems have arose as mentioned above.

I would advise you to seek a consult with an ophthalmologist to determine the cause and subsequent treatment.

16. Question by Ms Koh

Hi Dr, 

a) What causes cataract?

b) What are the symptoms?

c) How can one prevent the onset of cataract?

d) Are they any foods to take or avoid to prevent cataract?

e) If a white round opaque spot occurs in the centre of vision, is that cataract? If not, what is it and what can one do to make it go away? Thank you.

Answer by Dr Lim

Dear Ms Koh,

The most common cause of cataract is aging.

Cataracts typically begin after age 40 or older, but don't usually impair vision until after age 60.  The two preventable causes of cataract formation are smoking and UV radiation (sunlight) exposure.

Cataract can also occur at a younger age if you: have poorly controlled diabetes, take certain types of medication such as steroids, are born with it (congenital), or have experienced previous trauma to the eye.

The most common symptoms of a cataract are: Gradual cloudy or blurry vision, poorer night vision, colours seem faded, glares and halos, and frequent prescription changes in your eyeglasses or contact lenses (cataract may cause the refractive error to keep changing). Very rarely, a very dense cataract can cause high pressure in the eye resulting in acute eye pain, redness, and blurring of vision.

There is no known method of preventing cataracts from developing. Cataracts cannot be cured with medications.

You may reduce your risk of developing cataracts by:

• Protecting your eyes from ultra-violet (UV) light by wearing sunglasses

• Maintaining a healthy lifestyle and diet

• Treating diseases such as diabetes

• Not smoking

• Refrain from excessive rubbing or trauma to the eyes.

There are no proven foods to slow down progression of cataracts. However, having a healthy diet such as taking fruits rich in vitamin C, vegetables, and reducing alcohol intake, will help.

I am unfortunately not able to comment based on the information given above regarding the white round spot you see in the centre of the vision. I would advise you to see an ophthalmologist to have it assessed properly.

17. Question by Mr Soh

Dear Dr Jane Lim,

Generally, cataract Op is a swift, simple op.

My concern is: My wife is aged 75, has very high myopia ~1500 each, for both eyes, including a thin, stretched and elongated retina. Know that there is higher risk.

Believe she needs an ophthalmologist who specialises in retina, high myopia, cataract surgery. Deeply appreciate your advice and recommendation please.

Answer by Dr Lim

Dear Mr Soh, you are quite right that patients with high myopia are at an increased risk of retinal detachment after cataract operation, although this risk is small, and would be monitored for after cataract surgery. 

I am sorry that I am unable to recommend you specific eye surgeon in my current capacity. Most eye specialists would be able to handle her cataract surgery adequately.

18. Question by Ching Kee

Hi Doc,

Can I request SNEC for operation on cataract in my dominant left eye when the doctor at my last consultation 3 months ago said it doesn’t warrant it as mine cataract is minor.

I was prescribed with eye-drops.

Do I have to wait till vision of my left eye deteriorate further to warrant an operation?

Now, the vision of my left eye isn’t as bright as my right eye (I am short-sighted for left & right eye with astigmatism). Thanks as I wait for your advice.

Answer by Dr Lim

Dear Ching Kee,

In general, the need and timing of doing cataract surgery would depend on your individual visual requirements. For example, cataract surgery would be recommended when it starts to affect your daily living e.g. navigating, driving, cooking, watching tv. 

Do keep in mind that cataract surgery carries a very small risk of permanent, serious loss of vision, and should therefore be done when the benefits of surgery outweigh the potential surgical risks. 

If despite wearing glasses (given that you are short-sighted in the left eye), your left eye vision is still blur, you may consider cataract surgery and discuss this with your eye doctor.

19. Question by Goh KK

Hi Dr,

May I know we able to proceed cataract surgery mild case.

a) cataract will not heal only get worse as time past.

b) Do it early so could we could live with better sight. 

What is the pro and con of doing it early? Thanks.

Answer by Dr Lim

Dear Goh KK,

Cataract will gradually mature with time and will lead to more cloudy vision.

In general, the need and timing of doing cataract surgery would depend on your individual visual requirements. For example, cataract surgery would be recommended when it starts to affect your daily living e.g. navigating, driving, cooking, watching tv.

Doing it earlier may allow you to see clearer and reduce dependence on glasses depending on the intraocular lens implant option that you choose.

Do keep in mind that cataract surgery carries a very small risk of permanent, serious loss of vision, and should therefore be done when the benefits of surgery outweigh the potential surgical risks.

20. Question by KP Chng

Dear Dr, is it true that:

a) Once the eye’s natural lens is replaced with an artificial lens, any artificial lens that have deteriorated in quality cannot be replaced by another artificial lens?

b) In the past, artificial lens has a life span?

Answer by Dr Lim

Dear KP,

The artificial lens implant is permanent and meant to last a lifetime. You do not need to replace it.

However, in the very rare event that the artificial lens implant develops visually significant defects such as glistenings, or has shifted in position, an operation can be done for lens exchange or repositioning. 

It carries the same or can have increased risk of a cataract surgery such as permanent, serious loss of vision from infection, retinal detachment, corneal decompensation, raised intraocular pressure, posterior capsule rupture, and loss of lens zonules, and hence should only be undertaken if medically necessary.

21. Question by Victor

Hi Dr. Lim, few questions:

a) Is the Halo and Starburst effects during my night vision caused by the Cataract in my eyes or is it the Astigmatism or both.

b) If I were to do the Cataract surgery, would you recommend that I also get the replacement lens to correct my Astigmatism.

c) For the replacement lens I’m considering EDOF lens for my dominant eye which would correct distance and intermediate and Multi focal for near and intermediate for the other eye, your opinion please.

Answer by Dr Lim

Dear Victor,

Both cataract and astigmatism can cause halo and starburst effects. Other causes can include dry eyes and ocular surface problems.

Depending on the extent and type of astigmatism, you may benefit from toric intraocular lenses. Toric lenses are lens implants that can reduce astigmatism, thus reducing your dependence on glasses for distance. However, toric lenses do need to be positioned at a specific orientation to work. Do bear in mind that toric lenses can rotate, especially early on, which means that they can lose their desired effect, or even worsen your vision. This happens around 10% of the time. If significant rotation occurs, you may need to undergo an additional surgery to rotate the lens back to its intended position.

If you choose multifocal lenses, and are suitable for it, we would advise to implant multifocal lenses in both eyes (instead of having one eye with EDOF, and the other with multifocal). Using multifocal lenses allows you to reduce spectacle dependence for a greater range of vision (distant, intermediate, and near). They do not just correct for near and intermediate, unlike EDOF. Having multifocal lenses in both eyes allows you to maximise your benefits of reduced spectacle dependence. However, they commonly have visual side effects such as halos around lights, blurring or ghosting, some light-scatter, and decreased contrast sensitivity (visual quality) compared to monofocal IOLs. Not everyone is suitable for multifocal IOLs as optimal eye health is important to benefit from this lens.

Your eye doctor will need to assess your eye condition and perform certain assessments to determine which type of lens implant is suitable for you.

22. Question by George

Dear Dr Jane Lim, I have several questions to ask you, and they are:

a) Are there any eye drops which can prevent cataract from forming or growing?

b) Is there any scientific evidence to prove that carnosine supplement can prevent cataract from forming? Thank you.

Answer by Dr Lim

Dear George,

Currently, there are no eye drops proven to treat cataracts. The only effective treatment for cataracts is still surgery.

However, new research regarding potential eye drops to treat cataracts are still ongoing. They could possibly be a viable treatment option in the future. However, as of yet, there is no scientifically-proven eye drop that can treat or prevent cataract.

Regarding carnosine, there is currently no convincing evidence that N-acetylcarnosine drops reverses cataract, nor prevents progression of cataract.

23. Question by Terence

Dear Dr Lim,

a) How do I decide what lens to choose for my cataract surgery?

b) How do I decide whether to have my vision corrected 100% or to leave some degrees of short-sightedness? Thanks!

Answer by Dr Lim

Dear Terence,

Cataract surgery involves replacing the natural lens with an artificial lens implant (intraocular lens (IOL)). The focusing power of the intraocular lens can be chosen to reduce dependence on glasses after surgery.

The right type of lens choice depends on your visual needs, preferences, life style, and eye health.

There are 3 types of intraocular lenses:

1. Monofocal IOLs – which aim to reduce spectacle dependence for one distance, usually for distant/far vision. Glasses are then required for reading and near work. 
   - Toric monofocals also correct for astigmatism, allowing you to see distant things clearly without glasses most of the time. However, toric lenses do need to be positioned at a specific orientation to work. Do bear in mind that toric lenses can rotate, especially early on, which means that they can lose their desired effect, or even worsen your vision. This happens around 10% of the time. If significant rotation occurs, you may need to undergo an additional surgery to rotate the lens back to its intended position.

2. Multifocal IOLs which can reduce spectacle dependence for a wider range of distances: distance, intermediate (computer screens) and near (reading) vision. 
   However, they commonly have visual side effects such as halos around lights, blurring or ghosting, some light-scatter, and decreased contrast sensitivity (visual quality) compared to monofocal IOLs. Not everyone is suitable for multifocal IOLs as optimal eye health is important to benefit from this lens.

3. Extended depth of focus lenses can reduce spectacle dependence for distance and intermediate, but not near. You would still require glasses to see things up close. However, they have lesser visual side-effects such as glares and haloes than multifocal IOLs, but also require good eye health to benefit from this lens.

If you wish to reduce presbyopia (ie. To read without glasses) through cataract surgery, there are two approaches:

1. Using Monofocal IOLs -  Aim for clearer distance vision in one eye, and clearer vision at arms’ length in the other eye. With both eyes open, this allows you to combine both eyes’ range of focus, improving vision from distant objects to intermediate (computer screens). This is called a monovision strategy. However, you would normally still need glasses for certain activities like reading fine print, 3D vision (ball games), or driving, and not everyone can tolerate the imbalance in degree between the two eyes. That being said, near vision is at least partly restored and gives you more convenience to perform most activities without glasses. It also spares you from the side effects of multifocal IOLs.

2. Using Multifocal IOLs – allows you to reduce spectacle dependence for a greater range of vision (Distant, intermediate, and near). However, they come with visual side-effects and may not be suitable for everyone.

The above pros and cons of each lens needs to be taken into consideration according to your lifestyle and visual needs.

For example, if you frequently drive at night or work in dim lightings, you might not be suitable for multifocal or EDOF lenses as they can cause you to suffer more side effects such as glares, halos around lights, or loss of contrast.

If you do not have optimal eye health for example, you have severe dry eyes, glaucoma, or macular degeneration, you would also not be suitable for multifocals or EDOF lenses in general because these IOLs allow less light into the eye so they can worsen your vision if you already have a pre-existing eye disease.

Or if you’re naturally short-sighted and are used to reading a lot without reading glasses, or work at a computer all day, you probably would benefit from a monofocal IOL to aim for short-sightedness for close-up work, but you would have to wear glasses to see clearly for distance.

Your surgeon will need to assess your eye condition first and then you may discuss which IOL type is the best option for you based on your test results and eye health, lifestyle, and your preferences before you make your choice.

24. Question by Jasmine

Hi Dr,

My husband has been diagnosed with loose cataract condition and is scheduled for cataract surgery.  However, we had to postpone as he injured his arm and is great pain.

His eyesight has since deteriorated quite a bit since he was first diagnosed.  My question is if the surgery is delayed for too long will the loose cataract moved and cause other complications before surgery?

He has a past heart condition when stents were inserted.  This condition is now about 15 years old. Is an ECG required as pre-op test?  I don't see this being order during his previous pre-op test.

Answer by Dr Lim

Dear Jasmine, 

It is difficult to comment on your husband’s case based on the information given above. I am unsure what “loose cataract” refers to. It may be that he has a subluxed cataract – which means that the zonules (or ligament-like structures) holding the cataract is weak and the cataract is no longer stable in its original position within the eye. 

If he does have a subluxed cataract, the cataract may “loosen” more from its position and may eventually drop into the back portion of the retina. If that happens, he would require a longer surgery requiring more steps. If the cataract shifts into the front part of the eye, he may suffer from high eye pressure, which is an emergency. He may also develop chronic inflammation and high eye pressure long-term if not treated. I would advise him to proceed with his operation as soon as he can if he does indeed have a subluxed lens.

Doing an ECG is now no longer a compulsory pre-operative test for cataract surgery. Our nurses will determine his cardiac risk for the surgery during the pre-operative check up with a check list. Only if he is high-risk, then an ECG will be performed, and a doctor will review it.

25. Question by Shakeela

Dear Dr, thanks for the opportunity. Here are my questions:

a) My mum (above 70) has cataract, and is also a dementia patient. What will be the best treatment without needing to undergo GA? (Especially also for those difficult to cooperate)

b) Any exercises /diet that mum needs to follow (to reduce the impact of / to treat cataract)?

c) Can cataract be further prevented? How?  (For mum, and for her children)

Thank you, and looking forward to your advice.

Answer by Dr Lim

Dear Shakeela,

For those patients who are likely unable to cooperate, especially those with advanced dementia, they would most benefit from undergoing general anaesthesia (GA) during the cataract operation in order to carry out the operation safely.

Otherwise, if she is assessed to be fairly cooperative and compliant to keep her head still during the procedure, she may be fit for regional anaesthesia with sedation for her comfort. Regional anaesthesia comprises topical anaesthesia (anaesthetistic eye drops to numb the eye) with or without a peribulbar block (an injection to anaesthetise (numb) the eye given adjacent to the eyeball for movement control and pain relief).

The eye doctor seeing her would be able to assess your mum’s condition and determine the appropriate type of anaesthesia that your mum needs for the best surgical outcome.

The most common cause of cataract is aging. There is no known method of preventing cataracts from developing. Cataracts cannot be cured with medications.

You may reduce your risk of developing cataracts by:

• Protecting your eyes from ultra-violet (UV) light by wearing sunglasses

• Maintaining a healthy lifestyle and diet

• Treating diseases such as diabetes

• Not smoking

• Refrain from excessive rubbing or trauma to the eyes.

There are no proven foods to slow down progression of cataracts. However, having a healthy diet such as taking fruits rich in vitamin C, vegetables, and reducing alcohol intake, will help.

26. Question by Carol

Hi Dr,

Some have recommend using Betel leaves to wash the eye daily and this will reduce the cataract - how true is this?

Answer by Dr Lim

Dear Carol,

There is no evidence that using betel leaves to wash the eye will prevent or treat cataracts. The only known effective treatment for cataract currently is cataract surgery. I would also advise you to avoid doing so as using the water from betel leaves to wash your eyes is not sterile, and can contain chemicals that are harmful to your eyes.

27. Question by Jenny

Dear Dr Lim,

Will my optician be able to check for cataract in my eyes?

Answer by Dr Lim

Dear Jenny,

Opticians are not trained to perform visual examinations on patients. They are equipped with skills to dispense and fit glasses, though some may be able to provide contact lens fitting and management of contact-lens related complications.

Optometrists, on the other hand, depending on their level of training, may be able to perform eye examinations for common eye diseases such as cataract and refer them onto the ophthalmologist for further management.

28. Question by Marina

Dear Dr Jane Lim, my questions are:

a) Will everyone eventually have cataract if one lives old enough to develop it?

b) Is cataract avoidable if one takes good care of ones’ eyes?

c) What is the average age to go for operation to treat cataract?

I look forward to hearing from you. Thank you.

Answer by Dr Lim

Dear Marina,

The most common cause of cataract is aging. Eventually, almost everyone will develop cataract. Not all may not develop to the point of needing surgery, but you will eventually have some form of it.

In the majority of cases, people start to develop cataracts in their mid 40s.  It then affects 63.6% of people between 60 and 64 years, and 94.6% of people 75 years and older.

29. Question by Mr and Mrs Chan

Dear Dr. Jane,

How long is the procedure and recovery time for cataract surgery?

Thanks and best regards.

Answer by Dr Lim

Dear Mr and Mrs Chan,

The operation may take less than 30mins to an hour. It will be a day surgery procedure hence there is no need to admit to the hospital to stay.

You will be reviewed in the clinic the next day. If deemed suitable by your doctor, our nurses will contact you 1 week after your operation via teleconsultation.

You'll be subsequently seen in the clinic 4 to 6 weeks after surgery.

You will take two to four weeks to recover. Any eyeglasses needed will be prescribed between three to six weeks after your surgery.

30. Question by Evelyn

Dear Dr Jane Lim,

May I ask if it is safe to go for cataract surgery if I'm having eye floaters and eye flashes on both my eyes.

Appreciate your advice, thank you.

Answer by Dr Lim

Dear Evelyn,

If you have eye floaters and flashes, please see an ophthalmologist first to have a dilated retinal examination to check for any retinal tears or detachment. If the retinal check is normal, you may proceed with cataract surgery. Your ophthalmologist will assess whether the cataract needs to be removed.

31. Question by Chia Family

Hi Dr, 

My dad has Parkinson. He is 80.

a) How will cataract surgery be done for Parkinson's patient who is on Madopar (1/2 tablet four times daily) and Trihexypenidyl (1/2 tablet 2 times daily)?

b) Due to higher risk of cataract surgery for Parkinson's patient, what can we do to prevent his cataract from worsening?

Thanks.

Answer by Dr Lim

Dear Chia,

The method by which cataract surgery is performed for patients with Parkinson’s disease is the same as for those without. The risks would also be the same as those without Parkinson’s disease. However, depending on the stage and extent of tremors and involuntary movements, the type of anaesthetic given may differ.

If the patient is cooperative and the head and body tremors are unlikely to interfere with the surgery, the patient can do cataract surgery under regional anaesthesia with sedation for comfort (preferred method).

However, if the patient has difficulty cooperating with the procedure or has marked tremor and muscle rigidity that renders the patient impossible to keep their heads still during the procedure, the patient might need to do the surgery under General Anaesthesia (GA) in order to carry it out safely. However, GA carries a higher systemic risk than regional anaesthesia such as respiratory collapse, stroke, heart attack, worsening of Parkinson’s disease symptoms and mental state postoperatively.

Your eye surgeon will assess your father’s condition and determine the appropriate type of anaesthesia that your father needs for the best surgical outcome.

The most common cause of cataract is aging. There is no known method of preventing cataracts from developing. Cataracts cannot be cured with medications.

You may reduce your risk of developing cataracts by:

• Protecting your eyes from ultra-violet (UV) light by wearing sunglasses

• Maintaining a healthy lifestyle and diet

• Treating diseases such as diabetes

• Not smoking

• Refrain from excessive rubbing or trauma to the eyes.

32. Question by Dennis

Hi Dr,

What precautions should be taken before and after cataract surgery for a person with uveitis? Thanks and regards.

Answer by Dr Lim

Dear Dennis,

Depending on the type, cause, and complication(s) of uveitis, management for a patient with uveitic cataract differs from case to case.

In general, your uveitis should be inactive (no flare-up of the disease) at least 3 months before cataract surgery. You should continue with your existing maintenance medication regime (if you do have one). Your surgeon may give you steroids before and after the operation to reduce the risk of recurrence of uveitis and swelling of the retina (cystoid macular edema). Depending on the type of cataract and associated uveitic complications in the eye, uveitic cataracts may need additional steps during the surgery or a prolonged surgical time. Close monitoring after cataract operation is necessary.

I would advise for you to speak with your eye surgeon regarding the expected visual outcomes and potential risks of the eye surgery.

33. Question by Mei Chuen

Hi Dr,

My father did his cataract surgery. The doctor said that he had some Posterior Capsular Opacification (PCO) post-surgery.

May I know what would happen if he did not proceed with laser to remove the opacification? Thank you.

Answer by Dr Lim

Dear Mei Chuen,

Posterior Capsular Opacification (PCO) is a result of cells forming a membrane along the back surface of the bag (lens capsule) that holds your artificial lens. This can happen in up to 20% of patients after cataract surgery. If it is visually significant, it is normally treated successfully with a one-off minor laser procedure called a YAG laser capsulotomy. If it is not treated, his vision will remain blur or may increase in blurriness due to the thickening of the PCO over time.

34. Question by Helen

Dear Dr,

I have left lazy eye with mild cataract, could the surgery implant corrective lens improve my left eye vision?

Will it causes any problem if my left eye lens is far sighted and my right eye short sighted. 

Currently my glasses left eye is zero degree, right eye 350 degrees. Thank you.

Answer by Dr Lim

Dear Helen,

If you have been medically diagnosed with lazy eye (or amblyopia) before, doing a cataract surgery can partially, but not completely improve your vision. It will restore your eyesight to baseline (originally without the cataract, what you could see with the lazy eye). Doing cataract surgery does not treat lazy eye. Amblyopia or lazy eye is when vision does not develop properly during early childhood due to inadequate use. Due to the way the brain developed, it does not fully acknowledge the images seen by the amblyopic eye. Hence, amblyopia is not an eye disease and cannot be corrected directly by glasses or contact lenses nor cataract surgery. The treatment window is usually up to the age of eight. 

Your surgeon will need to assess your eye condition and will discuss which IOL type is the best option for you based on your test results and eye health findings.

35. Question by You BT

Hi Dr, I have 2 questions:

a) With floaters in eyes, would cataract operation lessen these floaters?

b) Why don’t doctors encourage cataract operation with one eye mono-focal lens and the other eye with multi focal lens? What are the reasons? Thank you.

Answer by Dr Lim

Dear BT,

Cataract operation will not lessen floaters. Cataracts and floaters arise from two completely different areas of the eye. Cataract is a condition when the natural lens in your eye becomes progressively cloudy. Floaters are caused by degeneration of the vitreous gel in our eye that forms tiny clumps of gel or cells that cast a shadow on the retina.

Conversely, cataract surgery may make pre-existing floaters appear more obvious because your vision would become clearer after the cloudy lens have been removed. However, an increase in floaters may indicate an underlying new retinal tear or detachment, and should be seen by an ophthalmologist to check your retina if you experience this.

We generally strongly recommend to implant multifocal lenses in both eyes if possible to realise the full benefits of the multifocal lenses and ensure balance in both eyes. Otherwise, one would have difficulty adapting or tolerating the difference between the two lenses.

36. Question by Mdm Lian

Dear Doctor,

I’m quite puzzled by the advice given from different doctors about when to have the surgery for Cataract.

It seems to me that doctors from Government hospitals advise patients to wait until the problem affects their daily activities. However, doctors in private practice would advise patients to have the surgery as soon as possible.

Hence, what is the optimal time to have the surgery done? Many thanks.

Answer by Dr Lim

Dear Mdm Lian,

While there may be differences in opinion between doctors regarding the optimal timing of cataract surgery, in general the need and timing of surgery depends on the patient’s visual requirements. For example, cataract surgery would be recommend when it starts to affect your daily living e.g. navigating, driving, cooking, watching tv. 

Cataract surgery  carries a very small risk of permanent, serious loss of vision, and should therefore be done when the benefits of surgery outweigh the potential surgical risks. The assessment of whether cataract surgery would be beneficial (relative to the potential surgical risks) would also be surgeon-dependent, and would need to be discussed with your ophthalmologist.

37. Question by Kian Yeow

Hi Dr Jane, Tthanks for your info on cataract.

Do I have to administer eye drops to keep the eye moist or too much eye drop will be easier for cataract to come?

Answer by Dr Lim

Dear Kian Yeow,

Lubricating eye drops, whether too much or too little, do not have any effect on the development of cataract. Lubricating eye drops work on a completely different area of the eye (the cornea) than from the cataract.

Ref: H24