About Refraction
A refraction test is usually given as part of a routine eye examination. It may also be called a vision test. This test tells your eye doctor exactly what prescription you need in your glasses or contact lenses.
Normally, a value of 20/20 is considered to be optimum, or perfect vision. Individuals who have 20/20 vision are able to read letters that are 3/8 of an inch tall from 20 feet away.
Vision issues are often the main reason a person seeks the services of eye doctor, but what does it really mean when we’re told that our vision is blurry because we have a refractive error?
We see the world around us because of the way our eyes bend (refract) light. Refractive errors are optical imperfections that prevent the eye from properly focusing light, causing blurred vision.
Why is this test used?
This test tells your doctor if you need prescription lenses, as well as what prescription lens you need to see properly.
- Astigmatism, a refractive problem with the eye related to the shape of the lens, which causes blurry vision
- Hyperopia, which is also known as farsightedness
- Myopia, which is also known as nearsightedness
- Presbyopia, a condition related to aging that causes lens of the eye to have trouble focusing