What are Prism Lenses? All The Details You Need to Know

What are Prism Lenses? All The Details You Need to Know

You have probably heard of prism lenses at your optometrist’s or they even prescribed them for you and you are wondering what they are.  

Indeed, these lenses are commonly prescribed despite the fact that they do not contain any focusing power.

They basically are used to trick the eye by creating the impression that objects are in different locations than they actually are. We’d like to delve deeper into what these lenses actually are and why they are important for vision health.

What are They?

By definition, prisms are triangular-shaped glass or plastic eye accessories that change the direction of light reflection or disperse light into a spectrum. Prism lenses are prescribed by optometrists and incorporated into ordinary lenses.

You may want to note that, unlike regular lenses, they do not come with focusing power. That means that they are not made to correct any refractive errors.

Why do I Need Them?

Okay, so prims lenses are not for correcting refractive errors with your vision. What are they for then? Here is a list of some of the eye issues that may be alleviated with the same.


*Double vision

*Fatigue and eye strain

*Difficulty focusing on the road while driving

*Shoulder, neck, and back pain

How do They Work?

Typically, the two human eyes work together by focusing on the same at the same time. Now, each of the eyes gathers special visual information and sends it to the brain to be processed. Once the information from both eyes gets to the brain, it is combined to generate a single image that you will then see clearly.

However, some people experience double vision because their eyes are misaligned and unable to function together to point in one direction simultaneously. This then results in the brain not being able to process the visual input from the eyes accurately. That simply means that you will not get a clear, single image.

This is where prism lenses come in…

That is because they work by turning the image to align correctly for one or both eyes. For instance, if one of your eyes is facing outward, prism lenses can move images to align to the position of the eye. On the other hand, if one eye sees images higher than the other, a base-down prism lens will come in handy for moving the image up.

Usually, your eye doctor will prescribe several prism lenses if you need different prism powers for different activities. This is particularly true if your eyes are intermittently aligned or when you experience eye turn because of eye fatigue or increased visual demand.

Are they a Long-term Solution?

Granted, prism lenses can help alleviate double vision when wearing glasses, but you need to know that they do nothing for your condition once you remove your glasses. That makes them a temporary solution.

To that effect, you may want to talk to your optometrist about vision therapy if you want a long-term or permanent solution for eye issues like binocular or double vision.

Keep In Mind

It typically takes a couple of days for one to get used to wearing prism glasses. Some people often report experiencing eye strain during this period of time. In rare cases, some people often talk of experiencing double vision, headache, nausea or even eye pain. In the event that one experiences such, it is advisable to consult the eye care professional who prescribed the glasses. In some cases, a new prescription or a complete frame refit may be recommended.

Also worth noting is that glasses with these lenses require to be worn all the time. One has to wear them the first thing in the morning and only remove them before getting to bed at night. Fortunately, with patience and perseverance, these lenses can significantly improve your eye health and enhance your quality of life.

Final Thoughts

Some people don’t fancy wearing glasses even if they have vision problems and that is where lenses come in handy. With prism lenses, you get to alleviate some symptoms but they do not offer a long-term solution. If that is what you are looking for, you would be better off with vision therapy.

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