On our blog, we have covered diplopia before, also known as double vision. This occurs when someone sees two images of one object. Prism correction can help to align the two images so that a person only sees one image.

The reason some people have double vision, is because the light coming into the eye and hitting the retina is falling on different parts of the retina in each eye. In order to see one image, light would need to fall in the same place on the retina in each eye.

How Does Prism Glasses Fix Diplopia?

Prism glasses are incredibly cool and can fix someone’s vision if they are seeing double. The prism added to the glasses bends the light before it travels through the eye. It redirects the light to the right place on the retina in each eye which then triggers the brain to fuse the two images together to make one picture.

Can Prism Glasses Fix All Double Vision?

The short answer is no. The long answer is that there are a number of double vision causes that prism glasses can fix:

  • Eye muscle problems
  • Brain related issues
  • Nerve related problems

Unfortunately though, there are some causes that prism glasses cannot help to correct. Double vision can be a sign of a seiours health condition. It is so important to make sure to seek professional care if you are suffering from double vision. Especially if your double vision:

  • Happens for unknown reasons
  • Is a new development
  • is caused by eye misalignment

How do you know if you need Prism in your glasses?

Like most eye correction methods, your eye doctor will determine whether you will benefit from prism being added to your glasses. There are a few different tests that can be performed if your eye doctor decides they are necessary.

  • Hirschberg Test – In this test a pen light is aimed at the eyes, and the lights reflection should appear in the center of the pupil in each eye. If the reflection is off center in either eye, there may be an alignment issue.
  • Krimsky Test – This test is used to find the severity of a misalignment that has been identified. This test uses a pen light as well with the addition of prisms of different strengths. The different prisms are placed in front of the eye, and when a prism brings the reflection in each eye to the center, the correct prism measurement has been found.
  • Cover Test – There are three different types of cover tests. The cover/uncover test, the prism and alternate cover test, and the Maddox rod test. Each of these tests will help your eye doctor to determine what type of double vision you have.

Prism Correction in eyeglasses can help to correct diplopia, or double vision. Be sure to always bring up any eye issues with your eye doctor in your normal ey exams. This will help your eye doctor to decide the best course of action to diagnose and correct any vision problems you are having!