Vision Flashcards
Dextoversion
looking to the right
Laserversion
looking to the left
Convergent
is crossed eyes
Divergent
is back to baseline
Saccades
Fast eye movements to switch gaze from one object to another
Smooth pursuits
Eye movements that follow a moving object
Vergence movements
Movement of the eyes toward or away from midline to adjust for different distances between the eyes and the visual target
Saccades might be
voluntary or reflexive and is processed in the pons
Smooth pursuit eye movements are used to
follow a moving object.
Optokinetic reflex
Adjusts eye position during slow head movements.
Example: When a person is walking, the head moves relative to objects in the environment.
Accommodation Reflex
Pupils constrict to
increase depth of field
Distance vision what happens to ciliary muscles?
Ciliary muscle is relaxed and the zonula fibers are taut
Near vision what happens to ciliary muscles?
Ciliary muscle is contracted and the zonula fibers are relaxed
Visual acuity
Snellen chart or pocket vision screener, newsprint, test with and without corrective lenses, test one eye at a time
Visual field test
one eye covered, pt. instructed to keep looking at examiner’s nose, bring item into field
Blind spot
the optic nerve passes through the surface of the retina, there are no photoreceptors
Primary visual cortex
Discriminate the shape, size, or texture of objects
Visual association cortex
Determines the colors and motion
Rubella syndrome
Rash on abdomen during first trimester
3 defects:
Cataracts
Sensory deafness – virus attacks spiral organ and cochlear duct
Patent ductus arteriosus
Vestibulo-ocular reflex (VOR)
Action of vestibular information on the eye position during fast movements of the head
Eye movement & Head Position. What contributes to these in our vision?
Head movements (vestibular information)
Visual objects (vision information)
Eye movement and position (proprioceptive information)
Selection of a visual target (brainstem and cortical areas)
