Human eye and colourful world pdf

human eye and colourful world pdf

(b) Why are the traffic light signals (or danger signals) of red color?
Compute the power of this lens.What type of spectacles should be worn by a person having the defects of myopia as well as hypermetropia?Ans i) Ciliary muscles: These are the muscles, which hold the eye lens.(ii) Accommodation: The ability of the eye lens to change its focal length is called accommodation.Class 10 Science Notes Chapter 11 Human Eye and Colourful World.Ans: - When the sun is overhead at noon, then the light coming from the sun has html and css for dummies pdf to travel a relatively shorter distance through the atmosphere to reach.The power of lens is given by power of a lens in dioptre 1/focal length of the lens in meter 1/0.5 -2 dioptre.
The band of seven colours is called spectrum.
Myopia (Short sightedness) : It is a kind of defect in human eye due to which a person can see near objects clearly but he can not see the distant objects clearly.

Its curvature can be adjusted with the help of ciliary muscles.(b) myopia : Myopia is corrected by using spectacles containing concave lenses of suitable focal length.For viewing distant objects, focal length of corrective lens, F -x -1.2 m, p 1 / f 1 / -1.2 -0.83D.The various colours seen are Violet, Indigo, Blue, Green, Yellow, Orange and Red.(ii) Cornea : It is a thin membrane which covers the eye ball.What is the nature and power of the lens required to correct the problem?
Myopia is due to (i) excessive curvature of cornea.