LASIK is essentially a safe and useful treatment that can be used for curing a range of eyesight difficulties. This is involves reshaping and even removing some aspects of the corneal tissue in order to alter the shape of the lens and to cure problems such as shortsightedness.
However it is certainly not for everybody, and there are certain eye problems that can’t be solved by LASIK. As such, before you get LASIK eye surgery, it is highly important that you first get LASIK pretests to ensure that you are a suitable candidate. This will involve a thorough examination of your medical history and lifestyle, as well as of the following tests:
Comprehensive Vision Analysis
This is essentially a thorough eye exam as you might expect when getting tested for glasses. Many aspects of your vision are measured here to measure your prescription while using cycloplegic eye drops. These dilate your eyes and also paralyze the focusing muscles in the eyes which allows the doctor to test your lenses rather than your ability to focus – the latter of which is not a problem for LASIK eye surgery.
Binocular Vision Assessment
This is used in order to test your eye alignment or binocular vision deficits which can otherwise interfere with the LASIK treatment. For instance if you ever had a lazy eye in childhood then this might make you more likely to fall into this category.
This process is used in order to examine ‘higher order aberrations’ in the optical system. Low order aberrations are the eye problems you may be familiar with and these include farsightedness, astigmatism, shortsightedness etc. However higher order aberrations can cause other symptoms such as poorer night vision, halos surrounding lights, glare and other problems.
This is a way of determining the exact shape of the cornea by using computer methods. Here the examiner can look at the shape of your cornea using colour maps where different colours indicate different gradients. Some corneal shapes might increase the chances of things such as keratoconus after LASIK treatments.
Corneal Thickness Measurements
This measures the thickness of the cornea which is important because very thin corneas might become damaged by the process of reshaping and removing corneal tissue.
Tear Film Tests
A good pretest should also exam the quantity and quality of your tears before deciding if you are a good candidate for LASIK and tears will be important for moisturising and protecting your eyes after the treatment. If you fail this part of the test then there are therapeutic and mechanical methods that can be used to improve the problem.
Pupil Size Measurements
This is important to ascertain the pupil size before and after dilation. Those that dilate a lot in low lighting for instance might experience more problems such as halos and glare following LASIK treatments. Subsequent developments in LASIK technology however have made this less of a problem, though the measurement is still an important part of the LASIK pretests.