10/17/2024
What is prism in eyeglasses prescription?
A prism in a glasses prescription is a special lens that helps with double vision and other binocular vision issues:
What it does:
Prism lenses change the direction of light so that it focuses on the retina, allowing the brain to see one image instead of two. This improves eye alignment and binocular vision.
How it works:
Prism lenses are triangular in shape and made of plastic or glass. They disperse light into a spectrum and change the direction in which light reflects.
When it's prescribed:
Prism lenses are commonly prescribed to treat conditions like Binocular Visual Dysfunction (BVD). They can also help with double vision caused by neurological conditions like strokes, head injuries, tumors, migraines, multiple sclerosis, and diabetes.
How they're used:
Prism lenses can be worn in one or both eyes. Temporary vinyl prism lenses, called Fresnel prisms, can be attached to regular lenses to try out prism lenses before getting permanent ones.
How they differ from other lenses:
Prism lenses don't contain focusing power and can't correct refractive errors like nearsightedness or farsightedness.
