HPL Ch 5 - The Eye and Vision

The part of the eye that is responsible for between 70% and 80% of the total focussing ability of the eye is: (P.75)

• the lens

• the cornea

• the iris

• the fovea

The amount of light allowed to enter the eye is controlled by the: (P.75)

• iris

• pupil

• cornea

• lens

Which of the following statement is correct? (P.76)

• When a person is tired, accommodation is diminished, resulting

  in blurred images.

• In order to focus clearly on a near object, the lens is flattened.

• In order to focus clearly on a distant point, the lens is thickened.

• The image is inverted and reversed by the cornea onto the retina.

Scotopic vision is vision through the functioning of: (P.76)

• rods

• cones

• lens

• iris

Which of the following statement is correct regarding rods? (P.76)

• The rods can only detect black and white.

• The rods are sensitive to colours.

• The rods are concentrated at the fovea.

• The rods are sensitive at high light levels.

Regarding adaptation: (P.78)

• When experiencing sudden high levels of illumination the eye quickly adjusts (approximately 10 seconds).

• the cones takes 30 minutes to adapt to night vision.

• the rods takes 7 minutes to adapt to night vision.

• the rods takes 30 minutes to adapt to light vision.

Myopia is a condition where: (P.81)

• it can be overcome by convex lens.

• the image forms behind the retina.

• the eyeball is too short.

• the eyeball is too long.

Convex lens is used to correct: (P.81)

• myopia

• hypermetropia

• astigmatism

• cataracts

Which of the following is incorrect regarding the use of contact lenses? (P.83)

• Contact lenses provide better peripheral vision and are not subject to misting.

• The use of bifocal contact lenses is recommended.

• Cabin decompression may result in bubble formation under the contact lens.

• The use of normal contact lenses by aircrew is permitted.

Which of the following is correct regarding colour blindness? (P.84)

• It affects visual acuity.

• Pilots are allowed to fly with this condition.

• It is caused by a defect in the structure of the cones in the retina.

• The most common is blue blindness.