Deficits Flashcards
Pupil structure
Controls the amount of light that enters the eye
The muscles that control pupil size are different than the muscles that control lens shape
Lens structure
Helps us sharpen focus during visual tasks
Lens shape is controlled by the cillary muscle
Retina structure
Where the cones and rods are
Allows us to view/perceive visual information, which then sends to the brain via optic nerve
PERRLA
Pupils equal, round and reactive to light and accommodation
Pupillary light reflex
Shine a light into the side of someones eye (directly is too uncomfortable)
The eye that has direct light stimulation will constrict (pupillary light reflex), and the opposite pupil, which is unaffected directly by the light, will also constrict (consensual pupillary light reflex)
Eye accommodation
The eyes ability to focus on objects both near and far away
Muscles within the eye work to cause the lens of the eye to become rounder (near vision) or flatter (far vision)
Convergence
Ability of your eyes to come together to keep an object in focus
Cause of double vision
With bi-ocular vision, it can be the eyes not working together
With monocular vision, it can indicate that they may have an impairment within the eye (such as retinal detachment)
Smooth pursuit eye tracking
The H test test
Common deficits include nystagmus, saccadic jumps within the smooth pursuit, and symptom provocation
Nystagmus
Abnormal eye movement where the eye quickly beats in one direction and slowly returns to its current start point
Saccades
A naturally occuring eye movement where the eye jumps from one fixation point to the next
However, can occur abnormally during eye tracking
All saccadic movements are relatively the same speed
Saccade testing
Looking from one object to another in horizontal and vertical planes
Saccadic dysmetria
An over or under shoot of the eyes when moving to look at a target
Skew deviation
Vertical misalignment of the eyes due to improper neuromuscular function
Testing skew deviation
Focus on an object infront of them, and while they focus, cover each eye one at a time. If skew deviation is present, the eyes will shift up or down to focus on the object
Sense angular acceleration
The 3 semicircular canals