Closing one eye and trying to read a letter on the wall 10 feet away is not just something they do on TV. It is one of the many techniques used to examine eyes and eyesight and in many instances can be used as a tool to help diagnose and treat poor vision. Eye exams are very important and here is some information on why that is the case and how they are conducted.
One of the very common tests given is the visual acuity test. Its purpose is to allow the doctor to analyze your visual sharpness. Bigger charts far away can be used to measure your acuity in terms of distance while smaller cards are used for near sight.
Another of the many tests that can be run is a test for colorblindness. This can detect whether or not you are colorblind as well as be used to check out if you have any other problems with your health that would have adverse effects on your eyesight.
One of the most common tests is the cover test. The way this test works is the doctor will have you cover one eye while you then have to identify something across the room with your uncovered eye. The test is used for far objects and then also for closer up objects. The outcome of this test is that the doctor will be able to tell whether your uncovered eye has to move or adjust to be able to clearly see the object. This can be used to determine whether you have strabismus or a potential lazy eye.
Ocular mobility tests may be run at some point in the eye exam. This test involves the movement of your eyes both fast and slowly. When in the slow portion, the doctor may have you look at a small light and have your eyes follow it as it moves side to side. With fast movements, you must move your eyes between two different objects. This test can determine whether you may have difficulty with sports vision or other things alike.
There are even more tests but it is important to remember not to run these tests yourself. You must go to the doctor for a proper eye exam and you should be going at least once a year to make sure your vision is and stays well.