Other Problems of the Eye

Other Problems of the Eye: Apart from the common defects described above, a person may develop other problems that hinder clear vision.

For example, looking at the sun with naked eyes during a solar eclipse can damage the retina.

Cataract: A common problem in old age is cataract, which gradually reduces the amount of light reaching the retina. The crystalline lens of the eye is made of proteins that are arranged in a regular pattern, which makes the lens transparent. When a group of these protein molecules get lumped in a region, it becomes opaque, and we say that a cataract has developed in the region. Gradually the cataract grows, and finally, the whole lens becomes opaque. And as the cataract grows, the ability of the person to see diminishes. To restore vision, the affected lens is surgically removed, and an artificial lens is placed in its place.

Astigmatism : Astigmatism is the most common refractive problem responsible for blurry vision. Anything other than the perfectly round contributes to abnormal connect. When the cornea is oblong shaped, it causes light rays to focus on two different points on the retina, instead of just one.Astigmatism can start in childhood or in adulthood.This defect can be corrected by using cylindrical lens.

Night Blindness. Deficiency of vitamin A contributes to blindness by making the cornea very dry, thus damaging the retina and cornea. Night blindness is the inability to see well at night or in poor light such as in a restaurant or movie theater. It is often associated with an inability to quickly adapt from a well-illuminated to a poorly illuminated environment.

Sample Questions

(More Questions for each concept available in Login)

Question : 1

A person is viewing a straight wire but the wire looks distorted to him. What defect is he suffering from?
A. Myopia	B. Hypermetropia	C. Astigmatism	D. None of these
Right Option : C
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Question : 2

Column - I	Column - II
A. Near sightedness	P. Area of no vision
B. Far dightedness	Q. Myopia
C. Cataract	R. Hypermetropia
D. Blind spot	S. Old age eye defect

Match the entities in column I to column II

A $rightarrow$ R, B $rightarrow$ Q, C $rightarrow$ S, D $rightarrow$ P

A $rightarrow$ Q, B $rightarrow$ R, C $rightarrow$ S, D $rightarrow$ P

A $rightarrow$ R, B $rightarrow$ Q, C $rightarrow$ P, D $rightarrow$ S

A $rightarrow$ Q, B $rightarrow$ R, C $rightarrow$ P, D $rightarrow$ S

Right Option : B

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Question : 3

The defect which is caused by oblong shape of the eye ball is ______________________.
A. Myopia	B. Cataract.	C. Astigmatism	D. None of these
Right Option : C
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