Refraction for Eyeglasses

According to the National Eye Institute, more than 150 million people in the United States have a refractive error – a defect that does not require the eye to focus images clearly on the retina. As a consequence, objects that are near or too far appear blurry and smudged. Eye refraction is the estimation of the required power for a person’s eyeglasses or contact lenses. This measurement is calculated based on a refraction test, which is typically a part of a routine eye examination. This test allows your eye doctor to find out what prescription you need in your glasses or contact lenses.

Also, a refraction test can help to detect other eye diseases as well as the likelihood that people will need vision correction. As a rule, a value of 20/20 is considered to be optimum, or perfect vision. If people don’t have 20/20 vision, they have what is called a refractive error. It means that the light is not bending correctly when it goes through the lens of the eye. If you’ve noticed trouble with seeing objects from close up or from a distance, visit our optical store at 280 Columbus Ave, Manhattan, and enjoy a comprehensive eye examination, including the refraction test. You can trust our highly qualified optometrists to get a proper diagnosis and glass or contact lens prescription.

Why is this test important?

The refraction test will not only help figure out what prescription lens you should use to have a perfect vision, but also diagnose common eye disorders and diseases, such as:

  • astigmatism, an imperfection in the curvature of an eye that causes blurred distance and near vision
  • presbyopia, the gradual loss of eyes’ ability to focus on nearby objects. associated with the aging of the eye
  • hyperopia (aka farsightedness), a condition of the eye where distant objects are seen more clearly than the objects that are up close
  • myopia (aka nearsightedness), an eye disorder where light focuses in front of, instead of on, the retina

The results of the refraction test can also help determine such eye conditions as:

  • retinal vessel occlusion, a blockage in the blood vessel at the back of an eye that can result in sight loss
  • macular degeneration, a common eye disorder among people over 50 that causes reduced or blurred central vision
  • retinal detachment, a condition where the retina pulls out of its normal position
  • retinitis pigmentosa, a rare genetic disorder of the eyes that damages the retina

Who should be tested?

Regular eye examinations are important for maintaining the health of your vision. Starting at no later than 3 years of age, everyone should have refraction testing. It allows detecting eye problems at the earliest stages and starting the treatment before there is any serious impact on vision and eye health. So, who should be tested and how often?

  • Healthy adults under age 60 with no complaints of eye trouble should have a refraction test every two years as a precaution
  • People currently wearing eyeglasses or contact lenses should have an eye examination every one to two years. Since eyes change over time, the prescription should be updated to match
  • People having diabetes should have a refraction test every year. A group of eye diseases, such as glaucoma and diabetic retinopathy, are associated with diabetes. It is thought that people with diabetes are at a greater risk for blindness than others
  • Older people over age 60 or those who have a family history of glaucoma should also have a refraction test each year. Regular eye exams will help detect glaucoma as well as other eye conditions associated with aging early and prevent eye damage
  • Everyone having any problems with their vision between exams should immediately see an eye doctor for another refraction test