Answer:
The invention of the Bifocals was announced on May 23, 1785 by Benjamin Franklin!
To learn more about Benjamin Franklin and his bifocals, check out this article!
http://www.antiquespectacles.com/topics/franklin/franklin.htm
Tag: glasses
Think About It Thursday: Why Do Some People Need Glasses?
On an eye chart each line has been assigned a number. During the eye test, patients will close or cover one eye and try to read each line of the chart until the letters become too small to read easily. If you can read the line labeled 20 from a distance of 20 feet, this means you have 20/20 vision. As a general rule of thumb, 20/20 vision is considered “normal vision”. If however, you can only read the letters/numbers on the top of the chart at 20/200, from only 20 ft away, you are technically legally blind.
If you have difficulty seeing things that are far away, you are considered “near-sighted”. Meaning that you can see things that are close to you, but things that are farther away appear fuzzy and out of focus.
If you have difficulty seeing things just in front of you, then you are “far-sighted”, meaning you are able to see things much more clearly that are farther away from you.
People wear glasses or contact lens in order to correct these impairments. Glasses and contact lenses use convex or concave lenses to bend the light entering the eye. This refocuses the eye, helping to correct vision problems.
Take a look at this neat resource for children to keep them active while watching TV! http://www.directvdeals.com/resources/kids-tv-activity-guide/
Resources: http://wonderopolis.org/wonder/why-do-some-people-need-glasses/#sthash.a3s7OqpS.dpuf