Who is not suitable?

The following conditions might not be suitable for LASIK

Most LASIK patients are between the ages of 21 and 65. The minimum age is 18 years old, but often short-sighted prescriptions have not stabilised until the 20s.

There is no upper age limit for laser correction as long as the eyes are healthy, though patients who are 60+ may be better served with a refractive lens exchange procedure depending on the prescription and eye anatomy, and Dr van Aswegen can advise you on this choice.

There are several possible conditions where LASIK surgery might not be advisable:

Severe refractive errors

If your prescription is very high or extreme, LASIK may not be a viable option. The treatment can greatly reduce the severity but you might still require glasses afterwards.

We can, however, treat around 98% of all short-sighted prescriptions, including those with astigmatism, if all other suitability criteria are met.

Dry eyes

This is the most common complication from laser eye surgery world-wide, but which is mainly avoidable with proper patient selection and pre-treatment to improve eye lubrication.

By 12 months after surgery, we see less than 0.5% of patients for ocular dryness and 0% by 2 years. We have a rigorous selection process and may spend several months getting your eyes ready for LASIK surgery. It is time very well spent.

Both the quality and the amount of tears you make are involved in the development of dry eyes, but quality is the biggest factor. Most dry eyes arise from excess evaporation.

Pre-operative therapies are directed at decreasing this back to normal levels.

Unstable prescription

Your prescription should be stable for 12 to 24 months before undergoing laser eye correction, either LASIK or PRK. Most prescriptions would be stable by age 21 and older.


If you have keratoconus or another corneal thinning problem, you will very likely be unable to have laser eye treatment.

Recent advances in stabilising and strengthening the cornea using collagen cross linking have allowed some patients to have surgery as part of the treatment of their keratoconus.

Large pupils

This was once considered to be more important than it is today. It links to the risk of experiencing problematic night vision after LASIK, including glare, halos and star-bursting of light. However, this risk is mainly associated with having large pupils PLUS the magnitude of the prescription, so that highly short-sighted patients are more at risk than mild to moderate myopia. Patients most at risk are those with very high prescriptions (e.g. -7.00 to -8.00 dioptres or higher) and large pupils (e.g. 8mm or bigger), and such patients need to be counseled appropriately.

Other eye problems

These include cataracts, glaucoma, corneal scarring, diabetic eye problems, prior eye surgery or other health conditions.

Immune disorders

These include rheumatoid arthritis, systemic lupus and other collagen vascular diseases. HIV is not an impediment to treatment if white blood cell counts and viral load are well controlled. Use of medications such as steroids and immuno-suppressants, e.g. methotrexate, 5-MP and azathioprine, can delay or affect proper healing of the eye after LASIK.

If we find any reason why LASIK or PRK is not appropriate for you, we will advise you accordingly.

Before your appointment we need you to please:

  • - Not wear your contact lenses at least 3 days before the appointment
  • - We will arrange a Pentacam and Oculyzer scan at the Cape Eye Hospital
  • - If you know your contact lens script, please bring it with you