What are prism lenses?

What’s All The Fuss About Prism?

All eye doctors (optometrists and ophthalmologists) use different types of lenses to improve your eye sight and vision. Regardless if you are near-sighted (myopia), far-sighted (hyperopia), or have astigmatism…You may need lenses to bend light differently to sharpen your focus!

However, sometimes the brain’s inability to use both eyes together can lead to a problem with binocular vision.  As a result, this can create trouble focusing (accommodation), turning the eyes inward (convergence), outward (divergence), or double vision (diplopia).


How Do Prism Lenses Work?

Therefore, to assist the brain in turning the eyes in proper directions, eye doctors will prescribe a type of lens known as PRISM to fix the problem.  In addition to compensating for the problem, prism can be used as a therapeutic way to assist the brain in learning how to fix the problem on its own.  This is something brain scientists call neuroplasticity. So what are prisms and how do they work?

In essence, optical lenses bend and focus light, known as refraction. Prism lenses, however, refract light a bit differently.  As a result, this produces a different result on sight and vision. Remember from science class, a prism looks like a pyramid with a base and a pointed top. Light passing through a prism will bend towards the base, while the image of the object viewed with the prism moves toward the peak.

Due to this shift, it appears the object we look at has moved in that direction. Using prisms in different powers and orientation, eye doctors can make a change in the direction of what we see.  As a result, you can experience single vision when there was double vision before.


So Do I Need Prism Lenses?

The path the signal travels to the brain is changed dramatically when prisms are used in the same direction on both eyes, a term called yoked.  Therefore, the brain changes the way it uses this new information.  This can have a dramatic impact on visual processing!

Using prism this way, the eye doctors at EyeXcel treat children with binocular vision issues affecting development or learningIn addition, adults who have suffered a brain injury or stroke can benefit from prism. It also may be helpful for the athlete wanting better vision skills to go to the next level.  Our job is to find the right direction and amount of prism that improves how a person’s brain uses the visual information.

So, if you are experiencing double vision, problems pointing your eyes in the right direction or focusing on the task at hand, make an appointment with the doctors of EyeXcel. Let’s find out if prism just might finally be the solution you’ve been needing!


Dr. Bruce Gilliland
, Optometrist at EyeXcel