Question

A person cannot see fundamental colors (red, blue, green). This defect is called
A. Myopia
B. Presbyopia
C. Color blindness
D. Astigmatism

Answer 1

Hint: Recall every defect of eye. The person with this defect may be able to focus the objects placed near to him as well as the objects placed far away from him. This defect is primarily due to absence of certain pigment cells.

Complete step by step answer:
To answer this question, let’s check every option one by one.
Myopia: Myopia is more commonly known as nearsightedness. As the name suggests, the person with Myopia is able to see the objects placed near to him, but cannot focus on the objects far away from him. This is primarily due to the shape of the eye which is unable to refract the light rays correctly.
Presbyopia: Presbyopia is the tendency of our eye which can’t focus the objects placed near to us. This is a natural process which comes with aging. Presbyopia can be cured with a surgery.
Color blindness: Color blindness does not mean the person with color blindness cannot see any colors. The color blind person cannot distinguish the primary colors such as red, green and blue. We know that red light has the longest wavelength, green has medium and bluish light has the shortest wavelength. Our eye has a retina which is covered with special nerve cells known as cones. These cones contain pigments that are sensitive to the wavelength of light. We can say the cones control our vision. If the cones lack the pigments which are sensitive to one of these colors, the person cannot be able to see these colors.
Astigmatism: We know that the person with astigmatism has blurry vision. This is the condition when our eyes are not perfectly round. This change in the shape of the lens in front of the eye cannot focus the objects clearly at any distances.

So, the correct answer is “Option C”.

Note:
The person with color blindness may not see any color if he lacks any of the pigments in the cones. This condition is known as Achromatopsia. Color blindness is a permanent defect and cannot be cured. To answer this question, students should understand the difference in the defects of eyes.