Light enters the eye through a thin membrane called

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This question was previously asked in

NDA (Held On: 6 Sep 2020) General Ability Test Previous Year paper

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Answer 1

CONCEPT:

Cornea: The transparent spherical membrane covering the front part of the eye
- Light enters the eye through this membrane.
- Most of the refraction happens here
Iris is a muscle in our eye that controls the size of the pupil. It dilates and contracts because of which size of the pupil varies.
- So we can say Iris controls the size of the pupil.
Retina: An image is formed on the retina.
Ciliary muscles are smooth muscle fibers. When the ciliary muscles relax the lens becomes flat and when they contract the lens becomes thicker. This change in curvature of the eye lens changes the focal length of the eyes.

F1 J.K Madhu 23.06.20 D3

EXPLANATION:

From the above, it is clear that light enters the eye through a thin membrane called the cornea. Therefore option 2 is correct.

EXTRA POINTS:

Name of the Part	Characteristics	Function
Eye Lens	transparent, biconvex structure in the eye	provides finer adjustment required to focus objects on the retina
Iris	The dark muscular diaphragm between the cornea and the lens	controls the size of the pupil
Pupil	An opening between the iris through which light enters the eye	regulates the amount of light entering the eye
Ciliary Muscles	Attached to the eye lens	hold the lens in position and modify the curvature of the lens.
Retina	the light-sensitive surface of an eye on which the image is formed	generate signals which are transmitted to the brain through optical nerves
Optic Nerve	Attached to retina	transmits visual information from the retina to the brain