Eye and vision

The eye is part of the brain. Because of the thickness of both eye nerves some say that about 35% of all information is transmitted through the eyes. 
The combination of the cornea, the lens, the retina and the nerve determine the visual quality. 

Many people claim to be "blind". By this they mean they require glasses. This is the start of a misunderstanding. Whether someone has good or bad eyes is not dependent on whether they wear glasses or not. Somebody with a refractive correction of -25 but has 100% vision is still considered to have good eyes. 

Imagine someone who can relatively see everything without the help of glasses. He/she has good vision, but if this person has an accident which damages his/her eyesight, he/she doesn't. Glasses won't help and his/her vision has changed in a day. 

When one wakes up in the morning the eyesight might be very good, but as the day goes on the eyes get tired, which can change the vision. However, not many people bother to acquire glasses for this situation. Just like most people are satisfied with their current glasses or contacts and don't bother updating them. This shows that the psychological aspect of one's vision plays a very important role. 

Basically, many people are happy with their current vision without correcting any possible (small) irregularities. It is possible that with a small correction the vision can improve dramatically even though it may already be 100%.

 Almost everyone is familiar with the way eyesight is tested. The most common test is the Snellen test, which is the card with letters that decrease in size. 

One hundred percent vision doesn't necessarily mean emmetropy, or a refractive correction of zero. 

Likewise, 100% vision doesn't necessarily mean high visual quality, good night vision or good contrast sensitivity. It also doesn't tell you anything about the absence of symptoms such as a glare, defects or regular or irregular astigmatism, tearing, glaucoma, irritation or headaches. 

Many of the aspects mentioned above can be detected by different tests. Often subjective elements are partly to blame. One can, for example, ignore the side effects of a glare. 

Despite preventing these side effects, most patients (75-85%) of all laser patients are (eventually) happy with their result. (Also see results).