Pinhole glasses operate on an optics principle that has been known for centuries. By decreasing the aperture size, the depth of field increases (i.e. the distance between the maximum and the minimum an object appears clear). It's the same reason people squint when they try to see better. So glasses based on this principle do work, but there are some drawbacks that keep them from being replacements to regular glasses, although in desperate situations they can be very handy.
Why do nearsighted people hold things very close to read? Why do farsighted people complain of eyestrain? Why do people need reading glasses as the get older?
What could be of enough importance in 1962 that if it was lost, a regular season NHL game would halt mid-play and the players would drop down on their hands and knees and look for it?
Of all the things you've seen in your life, I promise you none of them were of the reddish-green colour. Nor were any of them of the blueish-yellow hue. Some scientists refer to these two colours as the forbidden colours. But why cant we see them?
Every so often I come across a patient who has vision loss as the result of a parasitic infection. The parasite in question is usually Toxoplasmosis gondii, and it can cause significant damage to the human retina. But that may not even be the most terrifying trait of the parasite that is nicknamed "The Zombie Parasite".
The sun is so incredibly bright, that to safely view it, one would have to stack up at least 8 pairs (or more) of high-end sunglasses to meet the threshold deemed safe for the eyes. With the total solar eclipse crossing North America this year, now is a good time for a little reminder. NEVER LOOK DIRECTLY AT THE SUN.
There is an old joke about people living out in the prairies being able to watch their dog run away for days. Well if this is true (it isn't), then people living near the longest sightline on earth would be able to watch their dog run away for years.
Clean your furnace air ducts. Get teeth cleaned twice. Get approximately 10 haircuts. These are things that come at a modest annual expense that many of us do every year. Why? Because maintenance is a good form of prevention. So why then does the average person go 4 years between eye checkups?
We've all been told to avoid it, but is sitting too close to the TV actually bad for the eyes?
Fairly regularly at the end of an eye exam, a patient will say "Or maybe I should just eat more carrots?". I usually force a half-hearted laugh and a tepid agreement before explaining that Kale is actually what they should be consuming, and a little look back into life in WW2 Britain would explain where the carrot myth began.
Eyelid twitches are very annoying. And very common. The vast majority of them are completely benign, and harmless. The treatment of them is usually just reassurance and cutting down on stress, however there in an acedotal treamtnet that may work, although not clinically tested: quinine.
In 1750, legendary composer Johann Sebastian Bach was losing his eyesight. At the same time, a self-styled "healer" was "curing blindness" in flamboyant displays in town squares across Europe, to the delight of roaring crowds. They would eventually meet. What could go wrong?
At one time or another, we have all found ourselves quickly glancing up at a clock or a blinking light only to notice that it seems to briefly pause before resuming its normal rhythm again. How is this possible?
Eager job seekers and motivated employees are always trying to show how intelligent they are in hopes of landing a new job or scoring a coveted promotion. They try to talk smart, dress smart, act smart, and probably are smart, but it turns out one of the best validations of being smart might just be wearing their glasses (next to walking around with their IQ pinned to their name tag).