Breaking Down Prism Glasses and Their ImportancePrism glasses consist of a frame and lenses that contain prism. They are most commonly used to treat small vision misalignments (like vertical heterophoria) and large misalignments that cause double vision.
What Are Prism Lenses?Prism lenses are a specialized and unique eyeglass lens used to help individuals with more complex vision impairments. Prisms can be incorporated directly into traditional eyeglass prescriptions. Prism lenses alter your neuro-visual perception by changing the direction in which light (and the image that it contains) is reflected into your eye. Prism “moves” the image, allowing your brain to “think” that an object is exactly “where it needs to be” to be in alignment. If the brain believes everything is in alignment, there are no attempts made to realign the images, no eye muscle strain and overuse, and no additional negative symptoms.
Who Needs to Wear Prism Glasses?The most common reason your eye doctor might prescribe prism glasses is to correct image misalignments caused by conditions like vertical heterophoria or larger misalignments that cause double vision. Prism by itself does not correct nearsightedness or farsightedness. Therefore, most prism glasses containing prism are constructed in a way in which the prism is “ground into” the lenses, making for a superior product with better optics. These lenses that the prism is ground into also contain the optical prescription for correcting the astigmatism unique to the individual — solving multiple vision concerns with one pair of glasses.
What Conditions Could be Addressed by These Types of Glasses?Prism lenses could treat any muscle condition, neurological issue, or other eye condition that causes you to see double or causes your eyes not to align correctly:
- Strabismus (grossly misaligned eyes)
- Head injury
- Multiple sclerosis
How Do Prism Lenses Work?If the thought of looking through triangular prisms has you perplexed, you are not alone. Prism glasses take some knowledge to understand.
What Are the Scientific/Operational Features That Make Prism Glasses Work?There are different reasons you may experience double vision or other conditions treated by prism glasses. When you’re seeing double, your eyes aren’t working together to focus on a single object at the same time. Prism lenses bend light into your retina at a different angle than your standard prescription glasses. Prismatic effect is created by making one part of the lens thicker than the other, causing light (and the image it is carrying) to bend in a specific direction. Like corrective lenses, prism correction comes in different powers. You might only need a small amount of prism if your eyes are slightly misaligned, but you could need a higher power lens if you’re dealing with a neurological issue that’s severely impacting your vision alignment.
How do Traditional Lenses Work, and How Are They Different From Prism Lenses?You probably have a prescription for nearsightedness, farsightedness, or astigmatism if you normally wear glasses. These common vision problems happen because your cornea is uneven or your eyeball isn’t spherical. Traditional glasses are curved to compensate for your eye’s natural shape. For example, nearsighted people tend to have elongated eyeballs, which causes light to focus in front of the retina. Farsighted people have shorter eyeballs, which causes light to focus past the retina. Traditional corrective glasses have curved lenses that bend light differently than prism lenses; they refocus light directly to the retina so you can see clearly.
Do You Need Prism Glasses?If you are experiencing any symptoms of binocular vision dysfunction, vertical heterophoria, or long-term eye difficulties that have gone unsuccessfully treated, prism glasses might be the solution you need. Contacting your optometrist OR eye care professional for an eye exam is the first step to a correct diagnosis and getting prism glasses made for you.
Prism Glasses Eye TestingDuring your exam, your doctor may perform a variety of tests on your eyes to determine if prism lenses would be beneficial. Three common evaluations include: Hirschberg Test: The Hirschberg Test check for strabismus. A pen light is aimed at the eyes where the light's reflection should appear in the center of the pupil in both eyes. If the reflection is off-center in either or both eyes, strabismus may be present. Krimsky Test: In this evaluation, the degree of misalignment is calculated. While a pen light is aimed at the eyes, prisms of different strengths are placed in front of the eye. As the prism reflection is brought to the center of each pupil, the correct misalignment measurement can be found. Cover Tests: There are multiple types of cover tests, including the cover/uncover test, prism and alternate cover test, and the Maddox Rod test — all of which include a variety of testing individual eyes for sight ability and strength.
Do Prism Glasses Look Different?Prism glasses, on the surface, are just the same as any prescription eyeglasses you get from your doctor or any pair of cheap cheater frames you’d find at your local drug store. The prism is incorporated directly into the lenses, so there is typically no physical difference. Some prism glasses may feature larger amounts of prism focus placed in the lenses, however, the only noticeable difference to the naked eye would be minor thickening on one side of the lens.
Are Prism Glasses a Long-Term Fix?Prism glasses are a long-term, permanent fix for those struggling with various vision impairments. Sometimes referred to as “visual orthotic devices” within the vision community, prism glasses are a useful solution that can dramatically improve the quality of life for individuals.
What to Expect When Wearing Prism GlassesIf you have the right prescription and your glasses are aligned correctly, you should notice a marked reduction or complete elimination of your vision symptoms altogether. Prism glasses are designed to be a solution from the minute they are put on.
What Are the Potential Side Effects?There are no potential side effects associated with prism lenses or glasses. The major appeal to this vision solution is the absence of invasive treatment or surgery needed to address the eyesight concern. With no recovery time necessary, and an immediate improvement to vision symptoms, prism glasses are a growing solution for individuals suffering from non-traditional eyesight complications.
Discover if Prism Glasses Are Right For YouIf you have BVD or any other condition causing vision misalignment, contact Vision Specialists of Michigan to see if prism glasses can be a solution for your visionary needs, and an improvement in your quality of life.