Prism is used when there the two eyes are not functioning together as they should be.
Sometimes one eye can be up or down, while sometimes the eyes tend to sit out or in.
And occasionally you can have both vertical and horizontal eye misalignment. This is
one form of Binocular Vision Dysfunction (BVD). The prism or microprism can be used to
realign the eyes so that the eyes can be more comfortable, especially when working on
the computer or reading. Most patient do not see double, but double vision is a definitive
indicator that someone is a good candidate for prism.


Doctors that prescribe prism need to be certified and go through extensive training in
order to measure the prism correctly. If not done correctly, patients can be left with
dizziness, discomfort, anxiety symptoms or occasional double vision. Dr. Sarah has
been specially certified to prescribe prism for her patients.


The other aspect that is important is whether the lab that makes the prism frequently
calibrates their machines to accurately grind the prism into the lenses. If not done
correctly, the patient can end up more symptomatic than when they started.

The type of provider you are looking for if you need prism is a binocular vision specialist.
Specifically, a doctor that has completed Neurovisual Medicine Institute (NVMI) will be
able to prescribe smaller amounts of prism and more accurately.

When starting prism in your glasses, it is possible that over 6-12 weeks the eyes will
progressively relax and your prism will need to be adjusted at that time. This is very
common, since the eye muscles have been under strain and are still attempting to
compensate for the misalignment. Once the muscles get the help they need, the
symptoms can change and the prism may need to be adjusted.