Eye Glasses through the Magnifying Lens

Share

Do you suffer from poor eyesight? Have you ever imagined what your world would look like without your glasses? It would, definitely, be blurry. Everybody knows who invented the light bulb, but nobody really knows anything about the person/persons who lit up the world for poor-sighted people.

Glasses are based on lenses. Lenses gained their name from lentil beans because they are shaped, more or less, in the same way. They work by refracting rays of light; when light enters through a lens, it changes its direction, depending on the shape of the lens—concave or convex—one lens magnifying images, while another makes objects look smaller than they are.

The perfect lenses can be found in our eyes; normal eyes refract light correctly and present the viewer with a clear, non-blurry image. People with short or long eye-sight see blurry images because of the length of their eyeballs. For long-sighted people, the eyeball is too short, which makes near objects blurry because the light is focused at a point behind the retina. On the other hand, the eyeball of short-sighted people is long, which makes far objects seem blurry because light, in this case, is focused at a point in front of the retina. Glasses correct both problems by making the light focus on the retina.

While we do not know who invented eye glasses, some theories helped in laying the foundations for them. Ibn al-Haytham (c.965 – c.1038), or Alhazen, is an Iraqi scientist who is considered the Father of Modern Optics; in his Book of Optics, he wrote about refraction, reflection, and lenses. His ideas paved the way for the invention of spectacles, the telescope, and the microscope.

The invention of eye glasses stirs up controversy as no one knows who is the person that this invention should be accredited to, or when did they first appear. The first eye glasses probably appeared in Italy, in 1286. However, some people claim that corrective objects, which are far from the modern shape of glasses, appeared much earlier.

Seneca the Younger (4 BCE – 65 CE), a philosopher, Statesman, and the adviser to Emperor Nero, realized that a glass globe filled with water has a magnifying effect. Moreover, Emperor Nero (37–68 CE) was seen watching gladiatorial games through an Emerald Stone. The “reading stone” was invented during the 9th century; it is a piece of glass cut in half, when placed on a text, it magnifies it. It is believed that Abbas ibn Firnas invented the reading stone. All these were early attempts to improve vision and magnify objects.

Throughout ages, ideas, observations, and theories have contributed to our modern eye glasses. People with poor eye-sight are indebted to many people without which this article would have been blurry.


References
passmyexams.co.uk
article.sapub.org
greiche-scaff.com

Google Books
Optical Fluorescence Microscopy: From the Spectral to the Nano Dimension
Ed. by Alberto Diaspro

About Us

SCIplanet is a bilingual edutainment science magazine published by the Bibliotheca Alexandrina Planetarium Science Center and developed by the Cultural Outreach Publications Unit ...
Continue reading

Contact Us

P.O. Box 138, Chatby 21526, Alexandria, EGYPT
Tel.: +(203) 4839999
Ext.: 1737–1781
Email: COPU.editors@bibalex.org

Become a member

© 2020 | Bibliotheca Alexandrina