Do Lazy Glasses Actually Work? A Plain-English Explanation
Prism glasses look like a gag gift. Here's the simple optics behind them, what they do well, and where they fall short.
In this guide
If you've never tried them, lazy glasses look a bit ridiculous: a pair of frames with two small blocks sticking out the front. But the idea behind them is old, simple optics, and for the specific job they're built for, they do work. Here's exactly what's going on.
What lazy glasses actually do
Lazy glasses (also called prism glasses, bed glasses, or periscope glasses) put a small right-angle prism in front of each eye. Each prism bends the path of light by roughly 90 degrees, the same principle a submarine periscope uses.
The practical effect: when you're lying on your back, your eyes and face point at the ceiling, but what you see is what's straight in front of your body, such as a book held upright, a tablet, or a TV at the end of the bed. Your head stays resting on the pillow while your view goes where you want it.
So do they work?
For looking forward while lying flat, yes. The optics are not in question; a prism periscope has worked the same way for a very long time. What people really want to know is how it feels, and that's where expectations matter.
What it feels like the first time
- A short adjustment period. The view is coming from a slightly different direction than you're used to. Most people settle in within a few minutes.
- A narrower field of view. You're looking through a small window, so you see less of the periphery than with normal glasses.
- An upright image. Text and pictures should look the right way up; you're not reading upside down.
- A different way to hold things. You hold your book or device upright in front of you, the way you would if you were sitting up.
What they're good at
- Reading a book or e-reader while lying flat on your back
- Scrolling a phone or tablet without craning your neck
- Watching a TV placed at the foot of the bed
- Any time you'd rather keep your head resting on the pillow
What they're not for
- Walking, driving, cycling or operating machinery. Your view is redirected and narrowed; only use them while lying still.
- Correcting your vision. They aren't a prescription and don't replace glasses you need.
- Sleeping in. Take them off before you drift off.
How to get the best view
- 1
Get comfortable first
Lie on your back with a pillow that keeps your head comfortable and neutral.
- 2
Put them on like normal glasses
The prism blocks sit on the front of the frame and point toward the ceiling when you're lying down. If you wear glasses, they go over the top (see wearing lazy glasses over prescription glasses).
- 3
Hold your reading material upright
Bring the book or screen up in front of you at a comfortable reading distance, pages or screen facing you.
- 4
Give your eyes a few minutes
Nudge the frame up or down slightly until the image is centered. Once it is, it tends to feel natural quickly.
Frequently asked questions
Do lazy glasses work if I'm not lying down?
They're designed for lying on your back. Used upright, the prisms would point your view sideways or down at the floor, which isn't useful.
Do lazy glasses magnify text?
No. They redirect your line of sight but don't change focus or add magnification. If you need reading glasses to see print clearly, wear them underneath.
Can I fall asleep wearing them?
They're made for reading and watching, not sleeping. Take them off before you doze off.
Will they harm my eyes?
There's no reason to expect harm from using them as directed, but we're not eye doctors. If you have a vision condition or feel discomfort, stop and ask your eye care professional.
Lie back. Look straight ahead.
Horizontal prism glasses that bend your view by about 90 degrees, so your head can stay right where it's comfortable.
- Read, scroll or watch TV lying flat on your back
- Non-magnifying, fits over your own glasses
- Free shipping and a 30-day guarantee
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