Tag: the human eye and the colourful world

Questions Related to the human eye and the colourful world

The size of the pupil is controlled by the iris.

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

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Iris are the muscles that control the size of pupil to enable right amount of light to enter the eye.


Given statement is $True$.

Refraction of light in the eye occurs at

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

  1. The pupil only

  2. The cornea only

  3. The lens only

  4. Both the cornea and the lens

Show answer
Correct Option: D
Explanation:

Refraction of light in the eye occurs at both the cornea and the lens.

Like a camera, the human eye focuses light to produce sharp images. Light rays reflecting from distant objects are focused on the retina after they passed through the cornea.

Option D is correct.

The image formed on the retina of the eye is :

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

  1. Upright and real

  2. Virtual and upright

  3. Real and inverted

  4. Enlarged and real

  5. Larger than the object

Show answer
Correct Option: C

Match the following

i. Cornea a. Back surface of eye where image is formed
ii. Pupil b. Coloured part of eye
iii. Retina c. Membrane that refracts light and protects the eye
iv. Iris d. Transparent opening of eye.Light passes through it

 

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

  1. i-c ,ii-d,iii-a,iv-b

  2. i-a,ii-c,iii-b,iv-d

  3. i-d,ii-a,iii-b,iv-c

  4. i-b,ii-c,iii-d,iv-a

Show answer
Correct Option: A
Explanation:

Cornea is protective layer,it is transparent in nature. 

Pupil is the transparent opening of the eye. It lets light to pass through it.
Iris is responsible for characteristic colour of the eye.
Retina is the image forming screen of the eye.

Match the columns

i. amount of light entering into eye controlled by a. rodes 
ii. colour sensing cells  b. cones
iii.cells helping in vision in dim light c. iris
iv. junction of optic nerve and retina  d. blindspot
physics the human eye and the colourful world human eye and its working what is inside our eyes? human eye and defects of vision

  1. i-a,ii-b,iii-c,iv-d

  2. i-d,ii-c,iii-b-iv-a

  3. i-c,ii-b,iii-a,iv-d

  4. i-b,ii-a,iii-c,iv-b

Show answer
Correct Option: C
Explanation:

Iris controls the amount of light entering the eye.
Cones are colour sensing cells.
Rode cells help in vision in dim light.
At the junction of optic nerve and retina  there are no rodes and cones.No image is formed at this point as it is insensitive to light.This point is called blind spot.

The size of an object as perceived by an eye depends primarily on _____ .

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

  1. Actual size of the object

  2. Distance of the object from the eye

  3. Aperture of the pupil

  4. Size of the image formed on the retina

Show answer
Correct Option: D
Explanation:

Size of the object perceived by an eye depends primarily on distance of object from eye or eye lens. As magnification is given by:

$M=\dfrac{image\  distance}{object\  distance}$

What kind of lens is there in our eyes? 

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

  1. concave

  2. convex

  3. Plano-concave

  4. Plano-convex

Show answer
Correct Option: B
Explanation:

Answer is B.
Our eye lenses are convex lenses with variable focal lengths. The focal length of the eye lens is controlled by muscles according to the distance of the object from us that we are trying to see. The lens is flexible and when it is acted on by the ciliary muscle around it, the lens can be "flattened" to change the focus, or, when the muscle is relaxed, the lens can be assumed as having a more spherical shape. This is the principle of the eye to focus on objects nearer or farther away.

The retina is a delicate spot that receives images through the eye lens and makes us see the world. If it gets detatched, it is very difficult to join it back. Therefore, eye surgeons use

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

  1. Laser-beams for welding the retina

  2. Sound waves for joining

  3. Micro-knives for surgery

  4. Ultraviolet rays for surgery

Show answer
Correct Option: A
Explanation:

Laser surgery around retinal tear is often able to weld the retina to the underlying eyewall. This can prevented or limit retinal detachment.

Therefore Ane$\rightarrow$ Laser beams are used by the eye. Surgeons for welding the retina