Accommodation

Question 1

Heath’s components of accommodation are:

Answer 1

• tonic
• proximal
• voluntary
• vergence
• reflex (defocus)

Question 2

tonic accommodation accounts for about ____ D of accommodation

Answer 2

1-1.5 D of accommodation

Question 3

CA/C ratio is

Answer 3

the convergence accommodation per unit of convergence

Question 4

which is more clinically significant: CA/C or AC/A?

Answer 4

AC/A ratio is more clinically significant

Question 5

reflex accommodation is driven by

Answer 5

retinal defocus or blurring of the retinal image

closed-loop negative feedback control

Question 6

depth of focus number averages at

Answer 6

0.62 D

Question 7

depth of field ____ with decreasing pupil diameter

Answer 7

increases

Question 8

absolute presbyopes can measure about ____ D of accommodation

Answer 8

1 D

Question 9

depth of focus is measured clinically as the:

Answer 9

difference between the accommodative stimulus and the response

Question 10

lag= ____ accommodation

Answer 10

under

Question 11

lead= ___ accommodation

Answer 11

over

Question 12

what is more common: under-accommodation (lag) or over-accommodation (lead)?

Answer 12

under-accommodation (lag)

Question 13

amplitude of accommodation is the

Answer 13

total amount of accommodation available, measured in diopters

Question 14

amplitude of accommodation is the inverse of the:

Answer 14

near point of accommodation in meters

Question 15

do hyperopes gain or lose amplitude through their spectacle rx?

Answer 15

lose

Question 16

do myopes gain or lose amplitude through their spectacle rx?

Answer 16

gain

Question 17

push up amps measure _____ than minus lens amps

Answer 17

higher

Question 18

Donders push up or minus lens method:

-retinal image size increases greatly (up to 400%)

Answer 18

Donders

Question 19

Donder’s push up or minus lens method:

-retinal image size decreases slightly (up to 10%)

Answer 19

Minus lens

Question 20

Donder’s push up or minus lens method:

-proximal stimulation increases

Answer 20

Donders

Question 21

Donder’s push up or minus lens method:

-proximal stimulation is constant

Answer 21

Minus Lens

Question 22

Donder’s push up or minus lens method:

-target change is more natural

Answer 22

Donders

Question 23

Donder’s push up or minus lens method:

-stimulus change is continuous

Answer 23

Donders

Question 24

Donder’s push up or minus lens method:

-stimulus change is discrete

Answer 24

Donder’s push up or minus lens method:

Question 25

Donder’s push up or minus lens method:

-overestimates amplitude

Answer 25

Donders

Question 26

Donder’s push up or minus lens method:

-underestimates amplitude

Answer 26

Minus Lens

Question 27

push up test expected values for age 14, 50, and 75

Answer 27

14 D at age 10
2.5 D at age 50
0 D at age 75

Question 28

Hofstetter formula for average amplitude

Answer 28

18.5 D - (0.3 x age)

Question 29

Hofstetter formula for minimum amplitude

Answer 29

15 D - (0.25 x age)

Question 30

why are binocular measures almost always higher for accommodative amplitude

Answer 30

amplitude is increased with convergence

reflex accommodation + vergence accommodation