Photoreceptor Adaptation

Question 1

When does light adaptation occur?

Answer 1

When moving from darkness into bright light.

Question 2

What happens during light adaptation?

Answer 2

• Large amounts of rod pigments are broken down instantaneously, perceived as a “glare.”
• Pupils constrict
• Dramatic decrease in retinal sensitivity ; rod function cease = can’t see if you return to the dark

Question 3

Switching from the rod to the cone system takes how long?

Answer 3

cones & neurons adapt quickly; visual acuity is gained rapidly & improves in 5-10 minutes.

Question 4

What is dark adaptation?

Answer 4

Moving from bright light into darkness.

Question 5

What occurs during dark adaptation?

Answer 5

• Cones stop functioning in low light.
• Pupils dilate
• Rhodopsin will again accumulate in the dark
• Retinal activity is restored within 20-30minutes.