Tag: physics

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Multiple choice physics the human eye and the colourful world human eye and its working what is inside our eyes? human eye and defects of vision

The curvature of the eye lens can be modified by _____ .

  1. ciliary muscles

  2. iris

  3. pupil

  4. cornea
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The eye lens is made up of a fibrous, jelly-like material. Its curvature can be modified to change its focal length to some extent by the ciliary muscles. When the muscles are relaxed, the curvature decreases making the lens thin and the focal length increases. Similarly when the ciliary muscles contract the curvature of the eye lens increases making them thicker, this decreases the focal length of the eye.

Multiple choice physics the human eye and the colourful world human eye and its working what is inside our eyes? human eye and defects of vision

Which of the following optical phenomena is used in cinematography or movie projectors?

  1. Accomodation

  2. Persistence of vision

  3. Long sightedness

  4. Short sightedness
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Persistence of Vision is used in cinematography or movie projectors. Persistence of vision works because the human eye and brain can only process 10 to 12 separate images per second, retaining an image for up to a sixteenth of a second. If a subsequent image replaces it in this period of time it will create the illusion of continuity. Animation works by using an optical illusion. By presenting a sequence of still images in quick enough succession, the viewer interprets them as a continuous moving image. This is the same principle that enables live action film making and projection to work. Film theorists often refer to this illusion of movement as the persistence of vision.

Multiple choice physics the human eye and the colourful world human eye and its working what is inside our eyes? human eye and defects of vision

State whether true or false :

Pupil controls the amount of light entering an eye.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

True

The iris is the ring of pigmented tissue surrounding the pupil that varies in color. The iris opens and closes to control the amount of light entering the eye through the pupil. The pupil is the opening in the center of the iris where light enters the eye.

Multiple choice physics the human eye and the colourful world human eye and its working what is inside our eyes? human eye and defects of vision

The dark muscular diaphragm in the human eye that controls the pupil is:

  1. Iris

  2. Retina

  3. Cornea

  4. Sclera
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A. Iris is the muscular diaphragm in the human eye that controls the pupil.

B. Retina is a layer at the back of the eyeball that contains cells sensitive to light, which trigger nerve impulses that pass via the optic nerve to the brain, where a visual image is formed.
C. Cornea is the transparent layer forming the front of the eye.
D. Sclera is the white outer layer of the eyeball. At the front of the eye it is continuous with the cornea.