The laser surgery cannot correct all the eye defects in all people. Evaluation of the eye condition is necessary to determine whether this surgery will be successful for a particular person or not. The basic needs for the success of LASIK surgery are that your eyes must be healthy.
If your eyes have some infection that can affect the healing of the eye after the surgery, the surgery will not be successful. For example conjunctivitis, dryness of the cornea etc. in that case the surgery should be done only after clearing the problem. The surgeon may suggest certain eye drops to prevent the dryness after the surgery. You should be an adult to take this procedure.
The person should have stable vision at least for a year. Many teenagers experience changes in their glass prescriptions. The eyesight stabilizes most often in their 20’s.
It is not advisable for pregnant women to undergo this surgery. The hormonal changes during the pregnancy period cause the fluid level of the eye to increase. This will change the shape of cornea and hence the surgery should be avoided. Till the hormone levels are normal. Degenerative and auto immune disease also disqualifies a person from undergoing LASIK treatment. Examples of such diseases are HIV, AIDS, rheumatoid arthritis etc. if your body has trouble with healing, it will affect the outcome of the LASIK surgery.
Your eye prescription should be within the allowed limits. Severe myopia requires removal of too much corneal tissue in such cases ICL will be a better option for correction procedures.