Common Vision Problems 

The vision problems that occur most often are nearsightedness, farsightedness, astigmatism and presbyopia. These problems can affect both adults and children, and happen at any age. 

Nearsightedness 

Myopia (mi-OH-pee-uh), or nearsightedness, is a vision problem in which objects close up are clear, but things that are far away are blurry or difficult to see. Nearsightedness is caused by an elongated eyeball or a curvature in the cornea -- the clear front cover of the eye. Because of this elongation or curvature, light that enters the eye doesn't focus correctly, and the result is that faraway things look blurry. 

Myopia affects almost 30 percent of the people in the United States. The causes are unclear, but some research shows that it may be hereditary or caused by stress from too much up-close visual work. Usually, signs of nearsightedness appear in young children but grow until the age of 20. Sometimes myopia can show up in adults due to eye stress or other issues like diabetes.