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Erstellt / Aktualisiert 01.11.2017 / 27.01.2018
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15 Exakte Antworten 59 Text Antworten 77 Multiple Choice Antworten
Fenster schliessen

2: An optical system that demonstrates astigmatism is one whose point spread function is ------ . This means that the system's linespread function will depend on the  ----- . 

symmetric --- line orientation

asymmetric --- line orientation

Fenster schliessen

2: 

A system is a transformation from one signal—called the input—to another signal—called the output or the response of the system. Assume you have a system f with time-varying input x(t), and time-varying response y(t). Thus:

y(t)=f [x(t) ]

If you your system f was a linear system, its input-output relationship obeys two important properties: homogeneity and additivity. Which of the following statements express the propertiy of additivity mathematically?

f [x_1(t)] * f [x_2(t)] = f [x_1(t) * x_2(t)]

f [x_1(t)] + f [x_2(t)] = f [x_1(t) * x_2(t)]

f [x_1(t)] + f [x_2(t)] = f [x_1(t) + x_2(t)]

f [x_1(t)] + f [x_2(t)] = f [x(t_1 + t_2)]

f [x_1(t)] + f [x_2(t)] = f [x(t_1 * t_2)]

Fenster schliessen

2: In 1966, Campbell and Gubisch estimated the  ---    of the human eye using the ---   method. They found that for  ---  pupil sizes, the retinal image quality was mainly limited by  ---  .

linespread --- double pass -- small --- diffraction

linespread --- adaptive optics -- small --- diffraction

linespread --- double pass -- big --- diffraction

pointspread --- adaptive optics -- small --- diffraction

pointspread --- double pass --- big ---- diffraction

Fenster schliessen

2: The pointspread and linespread functions describe the spread (blurring) induced by an optical system on a point and a line respectively. Which statements are true

The linespread can be predicted, in general, from the pointspread

The pointspread can be predicted, in general, from the linespread

The pointspread can be predicted from the linespread if the pointspread is assumed to be symmetric

Fenster schliessen

3: Before reaching the photoreceptors, light passes through the:

cornea -> vitreous humor -> pupil -> lens -> aqueous humor -> retina

sclera -> cornea -> vitreous humor -> pupil -> lens -> aqueous humor -> retina

cornea -> aqueous humor -> pupil -> lens -> vitreous humor -> retina

sclera -> cornea -> aqueous humor -> pupil -> lens -> vitreous humor -> retina

sclera -> aqueous humor -> pupil -> lens -> vitreous humor -> retina

Fenster schliessen

3: Cones and rods are photoreceptors. Cones are mainly responsive in the --- , meaning they have  --- sensitivity to absolute light levels. They are concentrated in the  --- , and there are estimated to be about --- million cones.

day --- low --- fovea --- 5

night --- high --- peripher --- 100

day --- high ---- fovea --- 5

night --- low --- fovea --- 5

day --- high --- peripher --- 100

Fenster schliessen

3: Rods are not found in the  ---  [one word]. They express the photopigment  ---  and are mainly sensitive to  ---  wavelength light. There are estimated to be about  ---  million rods.

fovea --- Rhodopsin --- long (red) --- 5

peripher --- Rhodopsin --- short (blue) --- 100

fovea --- Rhodopsin --- short (blue) --- 100

peripher --- Rhodopsin --- middle (green) --- 5

fovea --- Rhodopsin --- short (blue) --- 5

Fenster schliessen

3: To bring near objects into focus, the ciliary muscles ---  , making the lens of the eye ---  , in a process known as --- . This capacity decreases with age such that by ---   years, accommodation amplitude is less than 2.5 diopters (compared to around ---   diopters for 20-year-olds). 

relax --- more thick --- Accomodation --- 40 - 50 --- 10

contract --- more thick --- Accomodation --- 50-60 --- 10

relax --- more thin --- Accomodation --- 50 -60 --- 5

contract --- more thin --- Accomodation --- 40-50 ---10

contract --- more thick ---- Accomodation --- 50-60 --- 5