DEC 19, 2017 3:37 PM PST

How Do Glasses Work?

WRITTEN BY: Xuan Pham

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
OCT 29, 2020
Chemistry & Physics
Einstein: Gravity? What Gravity?
OCT 29, 2020
Einstein: Gravity? What Gravity?
Try imagining a fictional conversation between Issac Newton and Albert Einstein: "The apple falls toward the ground ...
NOV 19, 2020
Chemistry & Physics
Unlocking the Secret of a Tasty Cold Drink
NOV 19, 2020
Unlocking the Secret of a Tasty Cold Drink
Sour beer isn't for everyone: its unique taste of acidity and tartness could excite some but turn off others.  ...
DEC 15, 2020
Immunology
The Possibility of Improving an Older Adult's Response to Vaccines
DEC 15, 2020
The Possibility of Improving an Older Adult's Response to Vaccines
A recent study published in the eLife journal examined how they can improve older adults' responses to vaccines ...
DEC 24, 2020
Chemistry & Physics
Novel Two-phased Particles are the Ultimate Authenticity Tag
DEC 24, 2020
Novel Two-phased Particles are the Ultimate Authenticity Tag
Counterfeit goods producers are flooding the global market with low-quality, sometimes dangerous merchandise and ripping ...
JAN 04, 2021
Space & Astronomy
Did Intelligent Civilizations Roam Our Galaxy 5 Billion Years Ago?
JAN 04, 2021
Did Intelligent Civilizations Roam Our Galaxy 5 Billion Years Ago?
Researchers have found that there were likely many intelligent alien civilizations sprawled across our galaxy billions o ...
JAN 13, 2021
Plants & Animals
Dwarf Giraffes Observed for the First Time Ever
JAN 13, 2021
Dwarf Giraffes Observed for the First Time Ever
The name “dwarf giraffe” certainly seems like an oxymoron, which is why scientists were shocked to observe t ...
Loading Comments...