Sensory - Visual Assessment

Question 1

A&P overview

Answer 1

the eye takes in light and converts it into electrical signals and sends it to the brain for processing

Question 2

overview of visual function

Answer 2

• vision is controlled by the interaction of light and nerve impulses transmitted to the nervous system
• retina uses special cells called rods and cones to process the light
• 3 types of cones in the retina: red, green, and blue

Question 3

overview of visual function

Answer 3

• 4 functions of the eye that allow for clear images no matter the distance: refraction, pupillary constriction, accomodation, convergence
• errors in refraction: myopia (nearsightedness); hyperopia (farsightedness); astigmatism
• light allowed to enter the eye is controlled by pupillary constriction (miosis) and pupillary dilation (mydriasis)

Question 4

cranial nerve

Answer 4

• II: optic > transports visual information from the retina to the brain and is therefore responsible for vision
• III: oculomotor > controls pupil constriction as well as eyelid and eyeball movement
• IV: trochlear > innervates the superior oblique muscles and allows eye movement in a downward and lateral motion
• VI: abducens > controls lateral movement of the eye

Question 5

presbyopia

Answer 5

• eye condition that everyone eventually develops (>40 years)
• results from ciliary muscles and lens losing their elasticity
• need for reading glasses

Question 6

assessment

Answer 6

• history: personal, family, nutritional, eye trauma
• inspection: visual inspection, note the symmetry of the eyes on the face, note any abnormal protrusion of the eyeball itself
• inspect eyebrows, eyelashes, eyelids, conjunctiva, iris

Question 7

vision testing

Answer 7

• snelling chart > visual acuity
• rosenbaum pocket vision screener ot jaeger card
• ishihara chart
• confrontation test
• corneal light reflex and six cardinal positions of gaze
• pupillary light reflex

Question 8

diagnostic studies

Answer 8

• ophthalmic examination: view retina, vessels and structures with ophthalmoscope; pupil dilation; red reflex
• CT, MRI, ultrasonography, radioisotope scanning
• slit lamp testing, intraocular pressure testing, corneal staining test, fluorescein angiography

Question 9

eye protection

Answer 9

• critical for preventing injury or loss of vision
• use of protective goggles at work and at home with high-risk activities is vital
• exposure to UV-B: damaging effects on the eye; association between excessive exposure and early formation of cataracts
• handwashing

Question 10

age-related changes

Answer 10

• anatomical changes occur naturally as people age
• not all decreases in visual ability are pathologic
• significant age-related changes occur: in the lens and the pupil; account for the majority of visual limitations experienced with advancing age
• loss of lens elasticity and yellowing
• conjunctiva is susceptible to chronic inflammation