Refractive Errors

Refractive Errors

What is refractive error?

A refractive error exists when the human eye cannot focus light properly. A highly common condition, refractive error is the main reason people wear contacts or glasses. Some people are born with refractive error or develop the condition in childhood, while many more develop refractive error as they age.

There are two main types of refractive errors:

  • A spherical error occurs when the focusing power of the eyeball is either too weak or too powerful to focus light on the retina. This can lead to myopia (nearsightedness) or hyperopia (farsightedness).
  • A cylindrical error occurs when the cornea or lens of the eyeball is irregularly shaped, preventing focused light from reaching the retina. Cylindrical errors include astigmatism, in which the cornea or lens is football- or donut-shaped, and presbyopia, in which the eye's natural lens loses the flexibility required to refocus light.

What are the symptoms of refractive error?

Blurry near or far vision is the main symptom of a spherical error.

People with astigmatism will have blurry patches in their vision, depending on the type and degree of their cylindrical error. People with presbyopia will have trouble transitioning between near and far vision - for example, when reading a menu and then looking up to find the waiter.

How is refractive error diagnosed?

Refractive errors are diagnosed by viewing an eye chart through lenses of varying power. Often times, dilating eye drops will be applied to the patient to increase the accuracy of the reading.

How is refractive error treated?

Depending on the type and severity of the refractive error, treatment options include glasses, contact lenses, laser eye surgery, or a combination of these treatments.

Learn more about treating refractive error at Temple.

To schedule an appointment with a Temple ophthalmologist or optometrist, click here or call 1-800-TEMPLE-MED (1-800-836-7536).