What is principle of kaleidoscope ?
Beautiful patterns are formed in a kaleidoscope because of multiple reflections
LIGHT
How to form multiple images?
Two mirrors inclined to each other give multiple images. Beautiful patterns are formed in a kaleidoscope because of multiple reflections
Helen A. Keller
Some visually impaired Indians have great achievements to their credit. Diwakar, a child prodigy has given amazing performances as a singer.Ravindra Jain, born completely visually impaired, obtained his Sangeet Prabhakar degree from Allahabad. He had shown his excellence as a lyricist, singer and music composer.Lal Advani, himself visually impaired, established an Association for special education …
Louis Braille
Louis Braille, himself a visually challenged person, developed a system for visually challenged persons and published it in 1821. Braille system has 63 dot patterns or characters. Each character represents a letter, a combination of letters, a common word or a grammatical sign. Dots are arranged in cells of two vertical rows of three dots …
What is the Braille
System?
The most popular resource for visually challenged persons is Braille. The present system was adopted in There is Braille code for common languages, mathematics and scientific notation. Many Indian languages can be read using the Braille system.
Care of the Eyes
Care of the EyesIt is necessary that you take proper care of your eyes. If there is any problem you should go to an eye specialist. Have a regular checkup—a) If advised, use suitable spectacles.b) Too little or too much light is bad for eyes. Insufficient light causes eyestrain and headaches. Too much light, like …
What is persistence of vision ?
It persists there for about 1/16th of a second.
The eye
The eye has a roughly spherical shape. The outer coat of the eye is white. It is tough so that it can protect the interior of the eye from accidents.Its transparent front part is called cornea . Behind the cornea, we find a dark muscular structure called iris. In the iris, there is a small …