Nearsightedness

• Nearsightedness occurs when the eyeball itself is too long or the cornea is too pointed. This causes the light that enters the eye to come into focus in front of the retina instead of on the retina. People who are nearsighted can see objects that are close to the eye very clearly but items in the distance are blurry. This condition can get worse during the teenage years because this is a period of rapid growth. People who are very nearsighted may be at higher risk for developing a detached retina.
  
  

Farsightedness

• In a person with farsightedness, the eyeball is smaller than normal. Light focuses behind the retina in hyperopic eyes; objects that are close to the eye like the words in a book are blurry and difficult to see. This condition can be seen in children; parents may notice the child squinting or rubbing the eyes. Hyperopia is often an inherited condition; however, the condition may improve in children as they get older.
  
  

Astigmatism

• In astigmatism, the cornea is irregularly shaped instead of being smooth and round like a basketball. This causes the light entering the eye to focus in different locations for the same object making the image look wavy or distorted. Both near and far objects can both appear blurry in people with astigmatism. Symptoms of astigmatism include eyestrain and headaches. Astigmatism can be found in eyes that have either myopia or hyperopia at the same time.
  
  

Presbyopia

• In young people, the lens of the eye is flexible and allows the eye to focus on both near and far objects. After age 40, the lens becomes stiff and it is more difficult to focus on close objects. This condition is called presbyopia and it causes difficulty with reading. It also is a natural result of aging. Presbyopia can also occur in eyes with myopia, hyperopia or astigmatism at the same time.
  
  

Considerations

• In most cases, nearsightedness, farsightedness and astigmatism can be corrected with prescription glasses or contact lenses. Once prescribed corrective lenses, a person should continue to wear them until an eye doctor says to stop. For people with presbyopia, reading glasses from drugstores may help improve reading vision; however, an eye exam is usually a good idea, especially if the person has one of the other types of refractive errors.