Common Defects of the Eye

Q.

Explain applications of lenses.

Q.

A colour blind girl is rare because she will be born only when

1. her father and maternal grandfather are colour blind.

2. her mother and maternal grand father were colour blind

3. parents have normal vision but grand parents were colour blind

4. her mother is colour blind and father has normal vision

Q.

Which lens is used for presbyopia? Give reasons.

Q.

A ___ lens is used to correct myopia and a ___ lens is used to correct hypermetropia.

1. concave, concave

2. convex, convex

3. convex, concave

4. concave, convex

Q.

A person who is colour blind cannot distinguish

1. Yellow and white

2. Red and green

3. Yellow and blue

4. Black and white

Q.

Color blindness is due to a defect in

Q.

A student is not able to see what is written on the black board while sitting in the last row. What is the defect of vision in this case?

1. Hypermetropia
2. Presbyopia
3. accomodation
4. Myopia

Q.

Concave lens: Short sight :: _________ : Long sight

1. Spherical lens

2. Biconcave lens

3. Cylindrical lens

4. Convex lens

Q.

A person suffering from a cataract has

1. elongated eyeball

2. excessive curvature of the eye lens

3. weakened ciliary muscles

4. opaque eye lens

Q.

Have a look at the posture of this girl who is reading a book and answer the questions which follow :
(a) Name the problem she is facing
(b) What are the two conditions shown in sections A and B of the eye as applicable to her.
(c) What kind of reading glasses does she need?

Q.

Define presbiopia.

Q.

Answer the following :
(a) What is the function of the lacrimal gland and where is it situated in the body?
(b) In what two ways is the yellow spot different from the blind spot?
(c) Name an old-age eye defect. What causes it?
(d) What is meant by power of accommodation of the eye?

(e) Mention the characteristics of the image that falls on the retina of the eye.

Q.

What is Hypermetropia? How it is corrected?

Q.

Enumerate the common defects of vision, their causes and the possible methods of correcting them.

Q.

Conjunctivitis is the disease of the_______

Q. Which of the following defect results due to the shortening of the eyeball from the front to the back?

1. Presbyopia

2. Cataract

3. Myopia

4. Hypermetropia

Q.

Differentiate between members of each of the following pairs with reference to what is asked in brackets.
(a) Myopia and hyperopia (Cause of the defect)
(b) Rods and cones (Sensitivity)
(c) Semi-circular canal and cochlea (Function)
(d) Rod and cone cells (Pigment contained)
(e) Dynamic balance and static balance (Definition)

Q.

Astigmatism is an eye defect in which some parts of the object are in focus while others are blurred.

1. False

2. True

Q. Sex-linked disorders such as color blindness and hemophilia are

1. Caused by genes on the X chromosome
2. Caused by genes on the autosome
3. Expressed only in men
4. Caused by genes on the Y chromosome

Q. Cornea (eye) absorbs UV- B rays and a high dose of UV- B causes inflammation of the cornea. Name the diseases which has the given symptoms.

Q.

Give scientific reasons for the following statements:

Color blindness is more common in men than in women.

Q. What is the cause of colour blindness?

Q. Prolonged deficiency of Vitamin A can lead to blindness.

1. True
2. False

Q.

Give the biological/technical terms for the following:

The lens of eye losing flexibility resulting in a kind of long-sightedness in middle aged people.

Q.

How rare is it for a girl to be colorblind?

Q. UV radiation from sun causes which of the following disorder of eyes?

1. Cataract
2. Dilation pupil
3. Some defect of retina
4. Glaucoma

Q.

Conjunctivitis is a contagious disease of the

1. Eye

2. ear

3. mouth

4. skin

Q. Given alongside is a diagram depicting a defect of the human eye. Study the same and then answer the question that follow:
(i) Identify the defect.
(ii) Name the parts labelled 1, 2 and 3.
(iii) Give labelled two possible reasons for this eye defect.
(iv) Draw a labelled diagram to show how the above mentioned defect is rectified.
Figure

Q.

What gender is colour blindness most common in?

Q.

Give technical/biological terms for:

An eye defect in which the cornea becomes uneven.