Some eye problems are minor and don't last long. But some can lead to a permanent loss of vision.
Common eye problems include
Refractive errors
Cataracts - clouded lenses
Optic nerve disorders, including glaucoma
Retinal disorders - problems with the nerve layer at the back of the eye
Macular degeneration - a disease that destroys sharp, central vision
Diabetic eye problems
Conjunctivitis - an infection also known as pinkeye
Your best defense is to have regular checkups, because eye diseases do not always have symptoms. Early detection and treatment could prevent vision loss. See an eye care professional right away if you have a sudden change in vision, if everything looks dim, or if you see flashes of light. Other symptoms that need quick attention are pain, double vision, fluid coming from the eye, and inflammation.
NIH: National Eye Institute