It seems that people use the words “eyesight” and “vision” quite often to mean the same thing.
Eyesight is tested through one’s ability to see images up close and far away (usually during an eye examination these are the charts with letters and numbers on them). At this point, the optometrist is testing for visual acuity. How accurately are your eyes seeing the image?
The term “vision” however, encompasses the idea of eyesight but goes a little bit beyond it. After testing for visual acuity, eye doctors also check to see if the eyes are working in sync, or what is called “binocularity.”
When the eyes are not working together, or one eye is working harder than the other, it is common to experience eye strain and headaches. If left untreated, eyes with poor binocularity can worsen significantly, resulting in conditions like lazy eyes.
Getting the appropriate corrective lenses made when you buy eyeglasses can make a world of difference.