Eye disease often causes blurry vision. However, problems with eye sight may also occur from the shape of the eye and how light reflects onto the back of the eye. In most cases, doctors easily correct these conditions with eye glasses or contact lenses. Knowing some of the common eye sight problems may encourage people with blurry vision to have an eye exam and correct the condition.
Near-Sighted
People who see well for reading and other close work but have blurry vision in the distance are considered near-sighted, a condition doctors refer to as myopia. A common condition, nearsightedness affects "nearly 30 percent of the U.S. population," reports the American Optometric Association. The condition results when the eye has a long, oval shape instead of being perfectly round, or if the cornea, the clear front of the eye, has "too much curvature," explains the American Optometric Association.
Far-Sighted
Farsightedness, also called hyperopia, occurs when the eye has an abnormally "short" shape, causing near objects to blur. With this type of eye sight problem, reading may be very difficult. An eye glass prescription or contact lenses will typically correct vision. Farsightedness frequently occurs in children with crossed eyes, says the University of Michigan Kellogg Eye Center. Crossed eyes require evaluation from an eye doctor, and treatment may consist of either patching the eye or surgery, though the child will most likely still require glasses for good vision even after the eyes realign.
Astigmatism
The cornea covers the front of the eye and allows light to enter the back of the eye. A perfect cornea has a round, ball-shape. If the cornea has an abnormal curve, like a football, the light entering the eye will not hit the back of the eye correctly, causing blurry vision, says The Foundation of the American Academy of Ophthalmology. Doctors refer to this abnormally shaped cornea as astigmatism. This condition commonly affects people of all ages, and doctors easily correct astigmatism with glasses or contacts, though if a person has a significant astigmatism, he may require special contact lenses that accommodate the corneal curve.
Presbyopia
During childhood and young adulthood, the natural lens of the eye has the ability to shift focus between objects in the distance and close-up. As part of the natural aging process, the elasticity of the lens gradually diminishes, resulting in a slow decrease in the ability for the lens to focus on close objects, a condition called presbyopia. Many people begin to notice these vision changes around age 45, when they "need to hold reading material further away," says the U.S. National Library of Medicine.
