Lecture 8- Ret on human eyes

Question 1

When you fog someone, you are moving the focal point ____

Answer 1

forward; in front of the retina

Question 2

what is the setup for static ret on human eyes

Answer 2

Provide a letter at least 16 feet away and project a 20/400 letter and use the projectors red/green filter to reduce glare. align yourself straight down the middle of the eye being tested, but make sure the pt can see the distant target with the other eye.

Question 3

Try to neutralize the meridian where you see the most plus first/least minus, that way you can see ___ in the second meridian.

Answer 3

against

Question 4

Incremental retiniscopy is ____ times faster

Answer 4

3

Question 5

during retinoscopy, _____ is called bracketing.

Answer 5

overshooting

Question 6

Three eyed retiniscopy allows each eye to have ret completed while the other eye is fixating on the distant target and controlling _____

Answer 6

accommodation

Question 7

what do phoropters allow doctors to control?

Answer 7

1. patient settings
2. spherical lenses
3. plano cylindrical lenses
4. auxillary lenses
5. which eye is moving

Question 8

what are the goals of refraction

Answer 8

1. find a lens equal but opposite to the discrepancy
2. provide clear and comfortable vision
3. allow for rapid adaptation
4. do no harm

Question 9

when the patients gets the new correction it begins a race between ____ and ____ of the glasses

Answer 9

adaptation; rejection

Question 10

There is a possibility of ____ refraction combinations

Answer 10

191,268

Question 11

refraction can be divided into 3 phases:

Answer 11

1. starting points; establish appropriate mind set
2. refinement
3. end points

Question 12

when establishing the appropriate mind set think about:

Answer 12

1. age
2. externals
3. case history
4. entrance tests

Question 13

If patient says tilting the glasses makes things clearer, think, change the _____. If pt says pushing the glasses closer to face make things clearer, think increase the ____

Answer 13

cylinder; minus

Question 14

exo at near is consistent with undercorrected myopia bc:

Answer 14

undercorrected accomodative convergence

Question 15

An amplitutde of accommodation that is low for the patients age suggests possible _____

Answer 15

hyperopia

Question 16

the subjective refraction has 3 main parts:

Answer 16

1. moncular subjective OD
2. monocular subjective OS
3. binocular balance

Question 17

what does MPMVA stand for

Answer 17

maximum plus to maximum visual acuity

Question 18

fogging the patient moves the retina ____away from clarity; it doesnt actually control accommodation but strongly encourages accommondation to go to 0. It works most of the time, but not all the time.

Answer 18

further

Question 19

the goal for the working sphere is to be the least amount of ____ or the maximum amount of _____ that provides the patient the best VA or MPMVA

Answer 19

minus; plus

Question 20

what are two ways to find the working sphere (the most plus)

Answer 20

1. count and calculate using eggers chart

2. duochrome test

Question 21

Since shorter wavelengths are bent more, their image plane is closer to to the ____-

Answer 21

cornea

Question 22

The duochrome test takes advantage of the spreading out of the images, dependent upon the length of the ______

Answer 22

wavelength.

Question 23

where the images fall relative to the retina depends on the _____ _____ determiniation

Answer 23

working sphere

Question 24

If green is much sharper it means that you have:

Answer 24

overminused

Question 25

how do you do the duochrome test

Answer 25

1. present with a line of letters a little larger than his MVA (usually 20/25 or 20/30) on the red green background
2. advise them to “look at the letters on the green side, then look at the letter’s on the red side and back to the letters on the green side” which side has the sharper and clearer letters?”
3. if they say red…add -0.25 of sphere power, if they say green add +0.25 of sphere power.

Question 26

if letters are equally clear on duochrome test, add

_____ sphere power

Answer 26

-0.25

Question 27

once the patient reports the first time the ____ side is sharper STOP

Answer 27

green

Question 28

what does the jackson cross consist of

Answer 28

plus plano cyl and minus plano cyl with axes 90 degrees apart stuck together center to center.

Question 29

The JCC does not change the spherical power because ____ ____ is 0

Answer 29

spherical equilvalent

Question 30

the dots on the JCC mark the ____

Answer 30

axis

Question 31

AFter doing ret, you find up to 0.50 of cylinder you must check the ____ first to see if there is really cylinder power yes or no.

Answer 31

power

Question 32

If tentative cylinder power is -0.75 or greater check the ____ first

Answer 32

axis

Question 33

while doing JCC for axis, and they say both views are equally blurry, what does this mean

Answer 33

the axis is probably in the optimal location

Question 34

While probing, if it is the same in two or more meridians or if it is white in all four meridians:

Answer 34

take out the -0.25 cylinder and check the vision

Question 35

when trying to decide if one and only one more reduction in fog is warranted ask:

Answer 35

if it is clearer, not smaller and darker