Stop Seeing Double: How Prism Glasses Can Help You
January 30, 2023 • 7:41 AM
Prism glasses are prescription glasses used to correct double vision. If you have double vision, instead of seeing one clear image of what you’re looking at, you see two blurry images. Prism eyeglasses help you see the world clearly again.
Let’s investigate what causes double vision and how prism glasses work to correct this dysfunction. We’ll also look at where to get prism eyeglasses that look so good, you’ll look forward to wearing them.
What Causes Double Vision?
If your eyes are perfectly healthy, they work together to help you see clearly. The light enters through your cornea and lens and falls in the correct place on both retinas. Your brain then combines the two pictures from the retinas to create a sharp image. This is called binocular vision.
However, if your eye alignment is slightly off, the light may fall on different parts of the retina in each eye. This eye misalignment sends two separate images to the brain, which struggles to overlay them correctly, so you end up with a blurry image — or double vision, otherwise known as diplopia.
Double vision can be caused by many different factors, including:
Eye conditions like dry eyes, severe astigmatism, or cataracts
Physical asymmetry, where one eye is higher than the other
Problems with eye muscles, which can cause conditions like crossed eyes (strabismus)
Neurological damage caused by a head injury, concussion, tumor, stroke, or even a migraine
If you have diplopia, you may experience difficulty with reading, depth perception, or concentration, or symptoms like headaches, dizziness, fatigue, and anxiety.
What Is Prism Correction?
Prism glasses have a triangular shape ground into the lenses. This bends the light before it enters the eye. It then lands in the right place on both retinas to create two images that the brain can combine to create a clear, single image for you.
It’s worth noting that prism lenses are specifically designed for double vision. They don’t have any focusing power so won’t work as reading glasses or help to correct for other refractive errors like farsightedness or nearsightedness.
Prism eyeglasses work well for many different causes of double vision — but not all. If you have double vision, or suddenly develop it, it’s important to visit your optometrist for an eye exam as soon as possible.
Your eye doctor will give you a prism prescription to correct for your double vision. You’ll see some numbers in diopters (much like for an astigmatism prescription) that indicate the level of prism correction you need. There’ll also be some letters that indicate where the base of the prism shape should be in the lenses, either horizontally or vertically, for example:
On the outer edge: Base out (BO)
On the inner edge: Base in (BI)
At the top edge: Base up (BU)
At the bottom edge: Base down (BD)
Note: Prism glasses don’t fix your double vision — they just help to correct it while you’re wearing your glasses. To address your vision issues more permanently, it’s worth exploring vision therapy. This helps strengthen your visual skills, training your eyes and brain to work better together.
What Do Prism Glasses Look Like?
Most prism glasses don’t look much different from other types of eyewear, except that the lens on one side might be slightly thicker than the lens on the other to accommodate the prism. This is easily hidden by choosing a slightly thicker frame.
If you want to try out prism glasses, you can get temporary Fresnel prisms fitted on your lenses. This is a vinyl sticker that is more noticeable — and your vision through them won’t be as clear — but they do allow you to test your new prescription before you have it permanently added to your eyeglasses. They’re also useful if your diplopia may be temporary or your prescription is changing.
Getting Used to Your New Prism Glasses
As with any new pair of eyeglasses, your eyes and brain will need a few days to adjust to the new prescription. Help them by wearing your new prism glasses as much as possible. However, as your depth perception will have changed with the new prescription, be careful when you’re first moving around.
To get the clearest vision, point your nose in the direction of the object you’re trying to see — don’t try to look out the sides of the lenses. The prism also needs to sit in a specific place in relation to your eyes, so the alignment of your glasses on your face is very important. If they keep tilting or slipping, ask your optician to adjust them or try other ways to keep your glasses from slipping.
Basic eye care like regularly resting your eyes and looking away from your screen towards the other end of the room can also go a long way.
During the adjustment period, you might experience some eye strain. Very occasionally, people also experience other side effects, like eye pain, headaches, or nausea. If these symptoms continue beyond about 10 days — or if you’re still seeing double despite your new glasses — contact your eye doctor again. Your new prism prescription may simply need some adjustment.
Where to Get Prism Glasses
Once you have your prism prescription, you’re ready to order your new pair of prism glasses. A great place to start is with Pair Eyewear’s huge selection of stylish and versatile frames.
Begin by choosing the Base Frame that best suits your face shape. Our Virtual Try-On feature allows you to take a photo of your face and then check how the different frames work for you. Our size guide may also help you make up your mind.
Once you’ve found your perfect Base Frame, you get to choose one or more Top Frames to suit your personality and interests. These are very lightweight and attach magnetically to the Base Frames, allowing you to switch them out at a moment’s notice. From our Classic Designs to our Sparkle range, you’re bound to find something that makes your eyes shine. Or you might choose to shade your eyes instead with Sun Tops or Sunglasses. No matter what Pair you go for, you’re guaranteed to look good.
Once you’ve picked out your look, you can get down to other important details, like choosing your lens type — whether that’s non-prescription, readers, single vision, or progressives — adding your prescription, and selecting any optional extras like blue light filters or light responsive lenses. For your prism prescription, we recommend choosing Premium Plus lenses, which are ultra-thin yet still give you all the lens power you need.
Finally, keep your Top Frames safe with a portable Top Frame case for your purse and a Wall Hanger to display them at home, so you can quickly choose your Pair (or Pairs!) for the day.
Prism Lenses Help You See the World Clearly
TL;DR, double vision is caused by a misalignment between your eyes. Light rays then fall in different places on your retinas, creating two images that your brain can’t align to create a clear picture. Prism glasses bend the light before it reaches your eyes, helping your brain show you a sharp image of what you’re seeing.
Once you’ve had an eye exam, choose from Pair Eyewear’s range of stylish frames, then add your prism prescription. Before you know it, your new Pair of prism glasses will arrive on your doorstep, helping you live life with more confidence and style.