Checking one eye a time

Mild differences in vision between the two eyes are very common, and the brain usually blends the images so seamlessly that you never notice. The difference becomes starker when one eye is covered.

In fact, many people don’t discover they have a “better eye” until they cover one eye at a time during an eye exam. This is one reason it’s helpful to occasionally check each eye separately at home, since a gradual change in one eye can be masked by the other. This is especially valuable if you have certain eye diseases like macular degeneration.

If you find that one eye suddenly sees much worse than the other, it’s worth scheduling a prompt eye examination.