Tag: human eye and defects of vision

Questions Related to human eye and defects of vision

Eye lens is a :

  1. transparent double-convex lens

  2. transparent double-concave lens

  3. transparent concavo-convex lens

  4. None of these


Correct Option: A
Explanation:

Eye lens is a transparent double-convex lens. Its focal length is adjustable in a manner such that a real image is formed on the retina.

Eye lens contains a watery liquid called:

  1. Aqueous humour

  2. Peroxide

  3. Vitreous humour

  4. None of these


Correct Option: A
Explanation:

Eye lens contains a watery liquid called the aqueous humour. Its major functions are immunity, nutrition, maintaining spherical shape and maintaining the required refractive index.

Amount of light entering the eye is controlled by:

  1. Iris

  2. Cornea

  3. Pupil

  4. Crystalline lens


Correct Option: A
Explanation:

Iris controls the amount of the light entering the eyes through the pupil by opening or closing. The iris is the ring of pigmented tissue surrounding the pupil that varies in color.

The eye consists of a screen called ______, on which the light rays are focused.

  1. Retina

  2. Iris

  3. Pupil

  4. None of these


Correct Option: A
Explanation:

The eye consists of a screen called retina which generates the sensation of sight. When light rays are focussed on it, an image is formed on the retina. The retina consists of light sensing cells which send signals to the brain, whenever such images are formed.

Two pont white are 1 mm apart on a black paper. They are viewed by eye of pupil diameter 3 mm. Approximately, what is the maximum distance at which these dots can be resolved by the eye ? [Take wavelength of light = 500 nm]

  1. 5 m

  2. 1 m

  3. 6 m

  4. 3 m


Correct Option: A

If you read the words of your book, the reflection is

  1. specular reflection

  2. diffused reflection

  3. may be specular may be diffused

  4. None of these


Correct Option: B

Image formation takes place by

  1. specular reflection

  2. diffused reflection

  3. Both (a) and (b)

  4. None of these


Correct Option: A

The distance of the eye-lens from the retina is $x$. For a normal eye, the maximum focal length of the eye-lens

  1. $= x$

  2. $< x$

  3. $> x$

  4. $= 2x$


Correct Option: A
Explanation:

Focal length of normal eye lens is equal to the distance between eye-lens and retina i.e, $x$  so that all rays converges on retina after passing through  eye-lens

The persistence of vision for normal human eye is :

  1. $1/{ 10 }^{ th }$ of a second

  2. $1/{ 16 }^{ th }$ of second

  3. $1/{ 6 }^{ th }$ of a second

  4. None of these


Correct Option: B

Refraction of light in the eye occurs at ............

  1. The lens only

  2. Cornea only

  3. both cornea and lens

  4. The Pupil


Correct Option: C