Also called a “vision test,” a refraction is given as part of a routine eye examination in our Princeton-area ophthalmology practice. This test allows your eye doctor to determine the best prescription lens for your eyeglasses and contact lenses. A value of 20/20 is considered optimum, or “perfect” vision.
When performing a refraction, your eye care professional uses an instrument called a phoropter, which resembles an oversized pair of glasses. As an individual gazes through the phoropter, the doctor flips different lenses in front of their eyes until the patient chooses the correct combination of lenses. The refraction is best known to the patient as the test during which the doctor asks, “Which is better: 1 or 2?”
The results of a refraction can determine the following visual conditions:
- Myopia, also known as nearsightedness
- Hyperopia, also known as farsightedness
- Astigmatism, a condition that causes blurry vision due to the shape of the cornea
- Presbyopia, a condition that causes blurred vision at near distances. This is due to a decrease in the ability of the natural lens to focus, and it’s often related to age.
The following conditions can frequently interfere with the refraction test’s ability to correct the patient to 20/20:
- Macular degeneration
- Diabetic retinopathy
- Retinal vessel occlusion
- Retinal detachment
- Retinitis pigmentosa
Because Medicare and many private insurance companies consider a refraction to be a non-medical test, it is not a covered benefit. Therefore, the refraction cost or fee is charged separately and payment is typically the responsibility of the patient.