Someone who is visually impaired may have limited vision because of an eye condition such as glaucoma, cataract, macular degeneration, or diabetic retinopathy. But next to eye conditions, vision can also be limited due to temporarily conditions. Because someone has had eye surgery which causes temporarily malfunction of the eyes. Or because of hay fever, which also has a limiting effect on the eyes.
There are also people who have lost their eyesight completely, which is called blindness. Some people are blind their entire life, and some people have lost their sight during their lifetime.