Eye refraction is a measurement of the needed power for an individual’s contact lenses or eyeglasses. This is worked out using a refraction test (better known as a “vision test”), usually conducted during a routine eye examination. Refraction tests provide an eye doctor with accurate measurements to provide prescriptions for patients that require contact lenses or glasses.
Refraction tests are also used to detect other types of eye problems and whether the person will require vision correction. People close to 60 or older, should have an eye test conducted every year, while younger individuals should be tested every two years. Eye tests are available widely through private practices and are typically covered by different vision-insurance plans. Eye testing is also made available through the state-funded programs dedicated to low-income residents.
The AOA, which stands for The American Optometric Association, states that “perfect vision” is usually expressed as a 20/20 vision.
What Can An Eye Refraction Test Find?
Refractions tests indicate whether a patient requires corrective lenses, along with the power of lenses that are needed. They also alert eye doctors whether patients have other conditions. Some of these include:
- Astigmatism – a refractive problem relating to the lens shape of an eye, which often results in blurry vision
- Myopia – nearsightedness
- Hyperopia – farsightedness
- Presbyopia – When one or lenses of an eye cannot focus, linked to structural changes of the patient’s eye caused by aging
At the same time, results from these tests are also used to help diagnose:
- Macular degeneration (an age-related condition where the blood vessels close to the retina become blocked)
- Retinal detachment (the retina detaches from the eye)
- Macular degeneration (an age-related condition which affects central-vision)
- Retinitis pigmentosa (this a genetic condition that causes retinal damage)
Who Should Have These Tests?
A refraction test should be performed regularly. People under 60 that are healthy without an existing vision problem, should go for a test at least every 2 years. When children turn 3 they should also start going for yearly or every second year tests.
People that wear corrective lenses should be going for vision tests every 1 to 2 years. The eyes change over the years so regular tests can assist optometrists or eye doctors to detect whether a prescription is needed or whether a different prescription becomes necessary when the corrective lenses are no longer providing adequate levels of vision improvement.