Fed up of wearing spectacles and contact lenses? If you are 21 years of age and above, and suffer from myopia (short-sightedness), hyperopia (long-sightedness), and astigmatism, you are a good candidate for LASIK, a surgical procedure that uses lasers to correct your vision. LASIK, performed as a day surgery, is quick and painless, and frees you from wearing spectacles and contact lenses.

Dr Mohamad Rosman, Senior Consultant from the Department of Refractive Surgery at Singapore National Eye Centre, gives detailed answers to your questions.


Question by chu

Hi Dr Melissa,

For eyes with different degrees of myopia and astig, is it advisable to do Lasik on just one eye, to correct the eyesight of just the eye with poorer eyesight?

Answered by Dr. Mohamad Rosman Consultant Dept of Refractive Surgery Service Singapore National Eye Centre

Unless the myopia and astigmatism of one eye is very low and the vision of that eye is relatively good, ie able to see quite well without glasses, it is advisable to perform LASIK in both eyes. This will enable good vision in both eyes after LASIK and also help with stereoscopic(3D) vision.

In general, I will advise my patients to consider performing LASIK in one eye only if their unaided vision in the better eye is 6/9 or better and that eye is not their dominant (also known as master) eye. Patients are generally unhappy if the vision in their dominant eye is poorer than their other eye. We also still have the option of performing LASIK on the unoperated eye later.


Question by tontonrokushi

Seeking enlightenment on Lasik

I am a myopic girl and have astigmatism detected in recent years. As at March 2012, my optician has confirmed that I am still not needing reading glasses. For a good part of my youth, I was wearing spectacles. I surmise this is partly because the eye specialist, whom my dad brought me to visit, was a staunch advocate of spectacles.

During my work life, I explored the optical world anew and discovered the freedom of switching between spectacles and contact lens. Alas contact lens proved practical during dance rhythmic and aerobic exercises, fun soccer etc. Besides, I like my eyes to look bigger. But in the recent 4-5 years, while back for my post-grad studies, it's funny now I have grown accustomed to wearing spectacles. I have unknowingly also completely forgotten about contact lens.

I think to myself, I may consider Lasik plan but 'after you' as I chat with my varsity buddy. She was SNEC Lasik 'guinea pig' (last year). May be it's just me, I was terrified to see her back to campus (after some rest) with blood shot eyes (like a cackling demon!) Afterwards, I shelved my Lasik plan. May be now it's my chance to seek authentic advice.

I am still thinking about the inevitable presbyopia (old age eyes) befalling on me, even though i may still not be needing reading glasses just yet. My diabetes is under control. But I have dry eyes only in the recent 4 years. Doctor, it would be almost magical if the Lasik mage can give me perfect vision.

I am curious if it can really correct for everything at one go, that is, correct the myopia, astigmatism and future presbyopia. Will the surgical outcome be better if I wait for the old age eyes to definitely set in first. Or is Lasik performed now, actually able to preempt presbyopia later on in life?

Must you check on the quantity and quality of the cornea tissue (which may thin with age?) before surgery is exercised. I also hear that patient is locally anaestheticised, I must not blink, but what if anxiety causes me to blink unconsciously, then does that cause accident during surgery.

What must I expect post-surgery recovery. I mean Pain- be truthful and tell me how bad is it? (I have a low pain threshold) Oh yes, is the post-surgery scary blood shot eyes a norm, doctor? Thanks in anticipaton of your reply.

Answered by Dr. Mohamad Rosman Consultant Dept of Refractive Surgery Service Singapore National Eye Centre

It actually depends on age. Base on your story, I assume that you are nearing presbyopia. The decision on when and how much to correct depends a lot on each individual needs. I would prefer to discuss with you in detail on this. However, in general, I would correct patients who does not have existing presbyopia fully, ie eliminate their myopia and astigmatism. These patients tend to prefer good vision in both eyes as they have not experienced the inconvenience of presbyopia yet. However, this means that they will require reading glasses when their presbyopia sets in, just like a normal person.

LASIK cannot treat presbyopia fully. I would consider performing monovision LASIK for my patients who are both myopic and presbyopic. Basically, this means that we leave one eye slightly myopic. As everyone uses both eyes to see, they will be able to see distance objects well with the fully corrected eye and near objects with the slightly myopic eye. However, not everybody likes monovision, as such I will examine these patients in detail and even test to see if they like monovision. In your case, if you are indeed nearing 40 years old (ie presbyopic age) we can consider a trial of monovision to see if you are suitable. In which case, if we can perform monovision LASIK on you, we may be able to treat your myopia, astigmatism and at the same time, delay the onset of presbyopia. But it would really help if I can examine and discuss the pros and cons of monovision LASIK with you. Performing LASIK now or later does not affect the surgical outcome.

As for your friend with bloodshot eyes, I suspect she underwent bladeless LASIK using the Intralase femtosecond laser platform. This is an older platform which needs to apply pressure on the sclera of the eye (ie the white part of the eye) during the LASIK procedure. As such, sometimes, this results in the rupture of fine blood vessels there, leading to subconjunctival haemorrhage (ie bleeding at the white part of the eye). Currently, there are newer lasers which do not apply pressure on the sclera and thus, do not cause such unsightly side effects. I usually use the newer Visumax femtosecond platform which does not cause this problem.

Yes, we will need to assess each potential LASIK patient thoroughly. We have to ensure that the patient has sufficient corneal thickness and that their corneas are normal before performing LASIK.

During LASIK, we will use a small instrument to help the patient keep their eyes open. So, even if the patient has a tendency to blink, his/her eyes will still be open during surgery. I have not had any patients who were able to close eyes during LASIK. Furthermore, the actual laser procedure is usually less than 30 seconds and most patients are able to control their blinking tendency for this short period of time.

You are most welcome. Most patients will experience some degree of discomfort after LASIK, usually lasting 4 hours. Most patients tend to have difficulty keeping their eyes open during this period and may tear excessively. Some patients will feel some irritation in their eye, something like feeling that there is an eyelash in their eyes. Very few complain of pain which affects them greatly. In general, after 4 hours, most patients are very comfortable and are able to do most normal activities.

Post-surgery blood shot eyes used to be the norm with the older femtosecond laser machines. However, this is no longer the case. Femtosecond lasers are needed to perform bladeless LASIK. Blood shot eyes are the result of the use of older femtosecond laser platforms which needs to apply pressure on the sclera of the eye (ie the white part of the eye) during LASIK procedure. As such, sometimes, this results in the rupture of fine blood vessels there, leading to subconjunctival haemorrhage (ie bleeding at the white part of the eye). Currently, there are newer lasers which do not apply pressure on the sclera and thus, do not cause such unsightly side effects. I usually use the newer Visumax femtosecond platform which does not cause this problem. Thus, the occurrence of bloodshot eye may depend on where a person undergoes LASIK and the femtosecond laser platform used.


Question by mosmos

I am now wearing spectacles with astigmatism and short-sightedness of more than 500 degrees on each eye. I also have dry eyes which I need to use the eye drop quite often during the day. I heard that people with dry eyes are not suitable for lasik. Is that true?

Answered by Dr. Mohamad Rosman Consultant Dept of Refractive Surgery Service Singapore National Eye Centre

Not all patients with dry eyes are unsuitable for LASIK. While it is true that LASIK may make the dry eyes worse, bladeless LASIK nowadays with femtosecond laser platforms creates thinner cornea flaps which reduce the occurrence of persistent post-LASIK dry eyes.

Many of my patients have dry eyes as a result of prolonged contact lens usage. However, most of them recover after and period of treatment and had LASIK done after recovering from dry eyes. They usually do not have problems with dry eyes after LASIK. As such, it is important to treat the dry eye condition before performing LASIK.

However, if you still have significant dry eyes after treatment, we can consider other forms of refractive surgery options which have lower risks of inducing dry eyes. These include, surface ablation procedures, phakic intraocular lenses and maybe even the newer SMILE (small incision lenticular extraction) procedure.


Question by imchristeanne

My sibling gone through Amblyopia surgery ages ago and had recovered well now he wants to undergo LASIK. Is advisable for one who under eye surgery before to go for lASIK?

Answered by Dr. Mohamad Rosman Consultant Dept of Refractive Surgery Service Singapore National Eye Centre

It really depends on what type of surgery your sibling underwent. The commonest surgery an amblyopic person goes for is a squint surgery. This surgery is done to straighten the amblyopic eye. As this surgery involves the muscle of the eye and does not affect the cornea, we can perform LASIK if the rest of the eye examination is normal. I have done a number of patients like this and they do very well after LASIK. However, it is still best if I can examine your sibling thoroughly and advise her/him accordingly. If the previous surgery, involves the cornea, LASIK may not be possible.


Question by pocoyosky

Dear Dr. Rosman,

Currently, I am wearing spectacles for myopia and very tempted to go for lasik, are there any side effects to our eyes or eye nerves if we do lasik? Also is lasik pernament vision correction or the correction effect only last for some years only?

Answered by Dr. Mohamad Rosman Consultant Dept of Refractive Surgery Service Singapore National Eye Centre

During LASIK procedure some sensory nerves to the cornea may be cut. This may result in increased dry eyes after LASIK. However, with bladeless LASIK, as the cornea flap created during LASIK is thinner, less sensory nerves are cut. As such, nowadays I hardly come across a LASIK patient with persistent dry eyes which affect his/her daily activities. There are other potential side effects of LASIK which occur in some patients, like experiencing haloes and glare at night. But again, these symptoms tend to resolve after a few months in most cases. It is best if I can examine you to determine the risk of side effects after LASIK.

LASIK is meant to be a permanent corrective procedure. And most patients are able to achieve this. However, regression (recurrence of myopia) does happen in some individuals. This risk is higher if that individual is younger, has high myopia and how the LASIK procedure was performed. However, we can perform an enhancement surgery (almost like a repeat LASIK) if this occurs, as long as there is sufficient cornea for this procedure.


Question by fetterhams

I'm 22 years old and I went for a lasik consultation recently. According to the consultant, even with lasik, my left eye (deg 1075) would still have a residual of 350 owing to insufficient corneal thickness. I would like to ask in your expert opinion, if there is a greater chance that through ReLex, the residual degree of 350 would be lowered, say to 250? Or would the result be almost similar, because my corneal thickness is such?

Answered by Dr. Mohamad Rosman Consultant Dept of Refractive Surgery Service Singapore National Eye Centre

Based on your story, it is likely that your cornea thickness is insufficient to fully correct your myopia. Both LASIK and ReLEx work by reducing a person’s cornea thickness, thereby reducing the refractive power of the cornea. A higher degree of myopia will require greater reduction in cornea thickness to correct the myopia. As such, if you are not suitable for LASIK as your cornea thickness is insufficient; ReLEx will not be able to correct your myopia fully too.

In your situation, the most optimal solution to reduce myopia will be a phakic intraocular lens surgery.


Question by soemyatthuzar

Dr rosman, I m short-sightedness and now I m wearing glasses. My degree keep increasing until 350. My left side and right side are 75 degree different. I am so tempted to do LASIK. My friend told me that she did LASIK a few years ago and no side-effects was occoured for her. May I know what are the possible side effects can get from LASIK? How many clinical trials were done for this and how was the result of analysis? If the procedure was failed, what is the next step?

Answered by Dr. Mohamad Rosman Consultant Dept of Refractive Surgery Service Singapore National Eye Centre

The commonest side effects of LASIK include post-LASIK dry eyes and night vision issues like haloes and glare at night. However, these symptoms tend to resolve after a period of time. Furthermore, with proper consultation, these side effects can be mitigated. Other potential side effects include regression (which I have discussed above) and inflammation. Other side effects or complications of LASIK are rare.

There are many papers published on the outcomes of LASIK and their complications. SNEC is probably one of the few centres in the world which audit their all their LASIK results and we have published a paper on the outcomes of over 37,000 eyes.

This paper shows that the outcomes of LASIK at SNEC is very good and the rate of complications extremely low.

Most people associate a failed LASIK surgery as one which was unable to correct their myopia fully and that they still require glasses after surgery. In most cases, if a detailed eye examination was performed, this problem rarely occurs. However, should someone be so unlucky, an enhancement surgery (in other words, repeating the LASIK procedure) can be performed as long as the individual’s cornea is thick enough. This usually corrects the problem.


Question by gcskck

Hi I am already 49 and have all these 3 symptoms such as myopia, hyperopia and astigmatism which is quite high. Currently I am on monthly progressive contact lens for all 3. May I know am I suitable to undergo LASIK to have both myopia and hyperopia done?

Answered by Dr. Mohamad Rosman Consultant Dept of Refractive Surgery Service Singapore National Eye Centre

In your situation, I would consider performing monovision LASIK as you who are both myopic and presbyopic. Basically, this means that we will leave one eye slightly myopic after LASIK.

This will allow you to see near objects with that eye. We will correct the other eye fully. As everyone uses both eyes to see, you should be able to see distance objects well with the fully corrected eye and near objects with the slightly myopic eye. However, not everybody likes monovision, as such I will need to examine you in detail and even test you to assess your suitability for monovision LASIK. But bear in mind that monovision LASIK cannot correct presbyopia fully, and that you may still need reading glasses to read very fine prints.


Question by joshng88

I would like to know what are the difference in price range between different practices, and does expensive = success rate?

Answered by Dr. Mohamad Rosman Consultant Dept of Refractive Surgery Service Singapore National Eye Centre

I am sorry that I am unable to comment on the prices of different practices. But currently, most centres charge slightly over one thousand dollars for LASIK in each eye. As you are probably aware, the prices may vary considerably from centres to centres. However, price does not guarantee success in all cases. Each individual is different and the skill of the LASIK surgeon and the technology of the laser machines used play an important role in ensuring a good outcome.

I would advise you to consider a reputable centre which performs detailed pre-operative examinations and has LASIK surgeons who are skilled and responsible if you are considering LASIK.


Ref: T12