10 Photopic Vision Flashcards
(35 cards)
1
Q
13 . What is Point Spread Function?
A
Distribution of photons during a shutter catch.
2
Q
- What are the basic units of photopic vision?
A
Photons
3
Q
- T/F: The visible light spectrum is narrow.
A
True
4
Q
- What is the approximate range of the visible light spectrum?
A
390 to 700 nm
5
Q
- Most of energy from the sun is in the _____ range.A) InfraredB) Visible LightC) Ultraviolet
A
C) Ultraviolet
6
Q
- When looking at a star how many cones are defining most of the image, and where are they located?
A
3-4 cones.Center.
7
Q
- What do the bumps in Point Spread Function indicate?
A
Optical aberration
8
Q
- T/F: Cones align towards the nodal point
A
True
9
Q
- What helps to guide the photons to the chromophore?
A
The inner segment guides the photon to the chromophore located in the outer segment.
10
Q
- T/F: Directional sensitivity of cones increases photon catch
A
False, directional sensitivity of cones decreases photon catch.
11
Q
- Out of the 5500 photons entering the eye, how many actually hit the chromophore?
A
~2900 photons
12
Q
- T/F: L/M cone ratio is 2:1.
A
False, L/M cone ratios vary.
13
Q
- The number of photons that reach the photoreceptors has an INVERSE or DIRECT relationship to their frequency?
A
Inverse.
14
Q
- How long is the “shutter time” for cones?A) 5 msecB) 100 msecC) 500 msec
A
B) 100 msec
15
Q
- Photon catch is integrated over a _____ time span.A) LongB) ShortC) Medium
A
B) Short
16
Q
- Which photoreceptor (rod or cone) is very sensitive and can respond to a single photon?
A
Rod
17
Q
Which photoreceptor (rod or cone) is very sensitive and can respond to a single photon?
A
Rod.
18
Q
- Chromatic aberration can be described as a _______ on the retina.A) BlurB) RainbowC) Cloud
A
B) Rainbow
19
Q
- Low frequency light (reds) focuses BEHIND or IN FRONT OF light?
A
Behind
20
Q
- High frequency light (blue) focuses BEHIND or IN FRONT OF light?
A
In front of
21
Q
- T/F: L cones are sensitive to short wavelengths?
A
False, L cones are sensitive to Long wavelengths.
22
Q
- What is peak sensitivity to a cone?
A
Increased probability of a photon to be absorbed by a cone.
23
Q
- T/F: L cones absorb 100% of all photons at different frequencies?
A
False, L cones absorb different frequencies of light at different percentages.
24
Q
- At a frequency of 510 Hz, L cones respond to how many photons out of the 2900 that hit the retina?a.) 250b.) 170c.) 310
A
b.) 170
25
20. What is the complex molecule that contains a chromophore and is found in the outer segment of a cone?
Rhodopsin
26
20. T/F: Rhodopsin is a photon-catching molecule that contains chromophore.
False.
27
20. T/F: Chromophore changes its shape from bent to straight when it absorbs a photon.
True
28
21. Out of every 3 photons, how many end up hitting a chromophore?
2 photons
29
21. T/F: Photoisomerzation is when a photon hits a chromophore isomer and changes it shape.
True
30
22. T/F: If 700 photons cause photoisomerization of chromophore, only a fraction of photons are in the Point Spread Function.
True. Only 170 of photons are in point spread function
31
09. ______ in the vitreous causes chromatic aberration secondary to difference in _______
Water, Index of refraction
32
10. TRUE or FALSE:Brown circles contain ~25% of the photonsSmaller concentric circles contain ~ 50% of the photons
FALSEBrown circles contain ~50% of the photonsSmaller concentric circles contain ~ 25% of photons
33
11. In the example from class, how many photons of a star's light hit the retina?A) 58B) 684C) 1452
C) 1452
34
12. Where is the image carried when the photons hit the cones? A) peripheryB) centerC) surrounding media
B) center
35
08. Which of the following is out of focus?A) L cones B) M conesC) S cones
C) S cones
