Question

In the figure of the human eye, the cornea is represented by the letter:

A. A
B. B
C. C
D. D

Answer 1

Hint: Human eye is considered as a camera to see this beautiful world, what makes all this possible is light which first enters a thin membrane called cornea.

Complete step by step answer:
In the above diagram, there are various parts of eye represented by A, B, C, D

We will see each of them:

A. Eye lens:

a.) Eye lens or simply lens is the transparent body enclosed in an elastic capsule.
b.) Made up of protein and water.
c.) The eye lens forms an inverted real image of the object on the retina.

Retina is a membrane having an enormous number of light sensitive cells. These cells get activated when light illuminates them and generates electrical signals. These signals reach our brain via optic nerve, which makes life beautiful.

B. Iris:

a.) Iris is behind the cornea and is a dark muscular diaphragm that controls the size of the pupil.
b.) Pupils regulate and control the amount of light entering the eye.

C. Cornea:

a.) As we already hinted, the thin membrane through which light enters.
b.) It is also the outer covering of the eye lens.
c.) Most of the refraction of light rays occurs in the cornea.

D. Aqueous humour:

a.) It is a thin, transparent fluid similar to plasma. It is mostly made up of water and it contains very little part of sugar, vitamins, proteins etc.
b.) Fluids nourishes the cornea and the lens and gives the eye its shape.

Our answer is option C. Cornea.

Additional Information:
a.) Curvature of the eye lens is modified by ciliary muscles. Thus, you may have seen when we bring a bright light source near our eye, the lens contracts while in dim light it expands. This is done by ciliary muscles to control the amount of light.
b.) Minimum distance through which humans can see clearly is 25 cm. Also known as Least Distance of Distant Vision.
c.) The maximum distance we can see is infinite.
d.) There are some defects associated with the eye, these are: Cataract, Colour Blindness, Myopia, Hypermetropia, Presbyopia.

Note: To remember the different parts of eyes, students must make the pattern either from front to back or back to front. Personally I suggest from front to back as light enters into eyes from the front side.