Entrance Tests Flashcards
____ contructs single perception from 2 retinal images
Sensory system
_____ system achieves a single image from both eyes; gives the distance of the target
Sensory
Poor binocular vision leads to
fatigue
eye strain
headaches
Binocular VA is in jeopardy in
Eye disease
Strabismus
Trauma
Name the 3 degrees of fusion:
- Simultaneous perception and superimposition (1st degree)
- Flat fusion (2nd degree)
- Stereopsis (3rd degree)
In order to get ____, binocularity has to be excellent to fuse fine disparity
stereopsis
The purpose of ____ is to measure fine depth perception by evaluating the ability to fuse stereoscopic targets
Stereopsis
We use the Worth 4 Dot when
stereopsis is below normal
Worth 4 Dot is used to
assess flat fusion at distance and near. Allows for the ability to detect a small central scotoma at near.
When testing for scotoma at near, make sure there is ____ with worth 4 dot at near.
normal flat fusion
Rough objective estimate and measurement of a deviation/strabismus. Evaluating the visual axes OU under binoc conditions at near.
(Just looking at the reflex)
Useful in young and cooperative patients.
Hirschberg Test
For this test, a penlight is held straight in front of a patient’s face at about 50 cm.
The patient is instructed to fixate on the penlight with both eyes open.
Hirschberg Test
3 possible corneal reflex positions for Hirschberg Test:
- Center of pupil
- Nasal to the pupil
- Temporal to the pupil
Hirschberg Test:
In the absense of a strabismus,
the corneal reflex should be centered in both eyes
Hirschberg Test:
In the presence of a strabismus,
the reflex will not be in the center of the deviated eye and it will be different from the relative angle lambda in that eye.
Hirschberg Test:
For 1 mm of estimated deviation, it is approximately a deviation of ____
22 prism diopters
When do you use Krimsky Test?
When you determine a deviation within the Hirschberg Test
This test is when you use prisms to determine the angle of deviation on Hirschberg Test.
Krimsky Test
For the Krimsky Test, prisms are placed in front of the ____ eye until the corneal reflexes are symmetrical.
fixating
Krimsky Test:
Base Out prism is used for _____
esotropia
Krimsky Test:
Base In prism is used for _____
exotropia
The Near Point Convergence (NPC) is to determine the
ability to converge and maintain fusion.
Near Point Convergence (NPC) test:
1) . Instruct the patient to look at the light
2) . Ask the patient if it is single or double; if double, move the target away further back
3) . Move the target towards the patient while paying attention to the eyes.
4) . Move it into the patient until the patient reports double or you see one eye loses fixation, take note of this distance (break point).
5) . Now move the target back again until the patient reports single vision or where you notice refixation. Measure this distance (recovery).
What all do you have to record for NPC?
1) . with/without correction
2) . the target used
3) . the distance (cm) where there was a break or diplopia (from bridge of nose or spectacle plane)
4) . distance of recovery
5) . deviated eye and the direction
6) . diplopia or suppression (break without diplopia)
Receeded NPC can cause:
- Binocular vision problems
- Eyestrain/asthenopia
- Reading difficulties
- Difficulties with near point tasks
______:
Measures a patient’s ability to accommodate (in Diopters)
Patient wears correction
Equiptment:
Near Point Accommodative Target
Occluder
Illumination
Amplitude of Accommodation