Defects in Human Eye

​Defects of Vision

• Myopia or near-sightedness or short-sightedness

• Hypermetropia or far-sightedness or Long-sightedness

• Presbyopia or old age hypermetropia

Myopia (near-sightedness)

A person with myopia can see nearby objects clearly but cannot see distant objects distinctly

The defect of eye called myopia (or short-sightedness) is caused :

• (i) due to high converging power of eye-lens (because of its short focal length)

• (ii) due to eye-ball being too long.

2. Hypermetropia (Long-sightedness or Far-sightedness)

Hypermetropia (or long-sightedness) is that defect of vision due to which a person cannot see the nearby objects clearly (though he can see the distant objects

The defect of eye called hypermetropia (or longsightedness) is caused :

(i) due to low converging power of eye-lens (because of its large focal length), or

(ii) due to eye-ball being too short.

Presbyopia (old sight)

Presbyopia is that defect of vision due to which an old person cannot see the nearby objects clearly due to loss of power of accommodation of the eye.

Cataract

​The medical condition in which the lens of the eye of a person becomes progressively cloudy resulting in blurred vision is called cataract

​Dual eye defect

Multiple Choice

A person cannot see the distant objects clearly (though he can see the nearby objects clearly). He is suffering from the defect of vision called :

• cataract

• hypermetropia

• myopia

• presbyopia

Multiple Choice

A person cannot see distant objects clearly. His vision can be corrected by using the spectacles containing :

• concave lenses

• plane lenses

• convex lenses

• contact lenses