DEC 19, 2017 03:37 PM PST

How Do Glasses Work?

WRITTEN BY: Xuan Pham
4 2 191

Millions of people worldwide suffer from vision impairments. In the US alone, over 4 million Americans over 40 are visually impaired, defined as having low vision or legally blind. For near-sighted (myopic) vision, light is focused in front of the retina, making close-by objects clear but objects in the distance blurry. In contrast, far-sightedness (hyperopic vision) is due to light focusing at the back of the retina; people with these conditions can see far but not close. The shape of the cornea also affects vision acuity; non-spherical cornea can lead to astigmatism, which is a form of blurry vision. Age also affects eyesight, as older people tend to have less flexible lenses to refract light.

For those whose vision problems can be corrected, the predominant treatment has been a set of glasses or contact lenses. But how do these seemingly simple devices work? In either form, the optical lenses enhance vision acuity by correcting light refraction to the retina of the eye, making objects clearer and more focused. The same premise is used in laser correction.
About the Author
  • I am a human geneticist, passionate about telling stories to make science more engaging and approachable. Find more of my writing at the Hopkins BioMedical Odyssey blog and at TheGeneTwist.com.
You May Also Like
JUL 22, 2018
Videos
JUL 22, 2018
How far can a single breath can go?
Longest distance swam underwater in one breath by a female using fins. Can you imagine being the Guinness World record-holder of that title? Marina Kazanko
JUL 31, 2018
Videos
JUL 31, 2018
Tired of Coffee? Try These Ideas for a Boost of Energy
A good strong cup of coffee first thing in the morning, at lunch, on a break or just about anytime can be a real boost. Not everyone likes coffee though, a
AUG 08, 2018
Videos
AUG 08, 2018
A Harbinger of Hope for Alzheimer's Patients?
The search for effective treatments for Alzheimer’s disease is ongoing, but overall, hasn’t been productive. Many companies, like pharmaceutica
AUG 09, 2018
Videos
AUG 09, 2018
History of Cannabis
The video above explains a brief overview on the history of cannabis and how the federal government, the states, and the general public have all made an im
AUG 17, 2018
Videos
AUG 17, 2018
Powering Greenhouses Using Food Waste
In simplest terms, food waste is food thrown in the garbage instead of being consumed. There is no use of throwing food and no benefit can come out of it.
AUG 18, 2018
Videos
AUG 18, 2018
Zombie Gene Protects Elephants From Cancer
Over an organism’s life, cells keep on dividing and with each division the risk of acquiring a mutation that may lead to cancer increases. Therefore,
Loading Comments...