Eyes

1

• Eyes
• Sensory organ
• External anatomy
• Eyelids-2 movable shades protect eye from
• injury, strong light dust
• Palpebral fissure- open space between eyelids
• Limbus- border between cornea sclera
• Canthus- corner of eye where lids meet
• Caruncle- inner canthus containing sebaceous
• gland
• Tarsal plates- upper lid, gives shape contains
• the meibomian glands sebaceous glands that
• secrete

2

• oily lubricating material for lids
• Conjunctiva- transparent protective covering of
• exposed part of eye
• Lacrimal apparatus- provides irrigation to keep
• conjunctiva and cornea moist lubricated
• Internal Anatomy-
• Outer Layer
• Sclera- tough protective white covering, covers
  iris pupil
  
• Cornea- sensitive to touch
• Middle Layer
• Choroid- dark pigmentation to prevent light form
  reflecting internally heavily vascular to
  
• Deliver blood to retina

3

• Pupil- round regular react to light to
  accommodation or focusing on an objective
  
• Lens- biconvex disc serves as refracting medium
  keeping viewed object in continual focus on
  retina
  
• Anterior Chamber- contains aqueous humor the
  produces continually by ciliary body delivers
  nutrient to tissue and drains metabolic wastes
  INTRAOCULAR PRESURE is determined by balance
  between amount of aqueous produced and resistance
  to its outflow at the angle of the anterior
  chamber
• Inner Layer
• Retina-visual receptive layer in which light
  changes into nerve impulses viewed through

4

• Ophthalmoscope see optic nerve, retinal
• vessels, general background and the
• macula
• Optic disc- fibers from retina converge to form
  optic nerve color varies from creamy
  yellow-orange to pink round or oval shape
  margins distinct sharply demarcated small
  circular area inside disc where blood vessels
  exit enter
• Retinal Vessels- include paired artery and veins
  extending into each quadrant Arteries brighter
  narrower the veins

5

• Visual pathways
• Objects reflect light
• Light rays refracted through cornea, aqueous
• humor, lens and vitreous body and strikes
• retina.
• Retina transforms light into nerve impulses which
  conduct through optic nerve optic tract to
  visual cortex
  
• Image formed on retina is upside down and reverse
  from actual appearance
  
• Thus right side of brain looks at left side of
  the world

6

• Subjective Data
• Vision difficulty-decreased acuity, blurring,
  blind
  
• spots ( did they come suddenly, in 1 or both
  eyes),
  
• do you have blind spots, halos or rainbows, any
  
  
• night blindness
• Pain- is it sudden, is it burning, sharp stabbing
  pain
  
• Strabismus, diplopia-history of crossed eye,
  double
  
• vision
• Redness, swelling- any infection now or in past,
  is it
  
• seasonal
• Watering, discharge- describe, hard to open eyes
  in
  
• AM, color of discharge
• Past history of ocular problems- injury or
  surgery
  
• Glaucoma- family history

7

• Use of glasses or contact lenses-when was last
• prescription checked which do you wear, how
  often
  
• change contact lenses
• Self care behavior- how often vision test? What
  are environmental conditions at work or home
  
• What medications are you taking
• Have you experienced any vision loss/ do you
  need
  
• large print to read or audio tape?
• Testing Visual Acuity
• Snellen Eye Chart-commonly used and accurate
  place chart at eye level, position client exactly
  20 feet away from chart hold a 3x5 card to
  shield 1 eye ask client to read the smallest line
  on chart can use

8

• E chart for people who cannot read record
• results as 20/20person is standing 20 ft away
  
  
• from chart and the lower number is the
  distance a
  
• person can read that particular line if 20/30
  
  
• person standing 20 ft away from chart and the
  
  
• bottom line is what a person with normal
  vision
  
• can read at 30 ft
• Near Vision- test for people oer40 who have
• difficulty reading pg 307
• Confrontation test- gross measure of peripheral
  vision See pg 308
  
• Pupillary Light reflex- in darken room, client
  gazes
  

9

• into the distance, advance light form side and
  note
  
• the response will see constriction of the same
• sided pupil and simultaneous constriction of
  the
  
• other pupil
• Infants
• Eye function is limited a birth
• Peripheral vision is intact in newborn.
• Eye exam maybe deferred at birth because of
  birth
  
• trauma or instillation of silver nitrate
• Birth -2wks- refusal to reopen eyes after
  exposure to bright lights may fixate on an
  object
  
• 2-4 wks- fixate on an object

10

• By 1 mo- can fixate and follow light or bright
  toy
  
• 3-4 mo.-fixate, follow and reach for toy
• 6-10 mo- fixate, follow toy in all directions
• Allen test- picture cards, screens child at 2,
  contains familiar object as birthday cake, teddy
  bear, tree, house, etc go from close up then go
  to 15 ft.
• Older Adult
• Peripheral vision may be diminished
• Central acuity may decrease
• Atrophy of elastic tissue may show wrinkles or
• crows feet.

11

• Lacrimal apparatus may decrease tear production,
• causing eye to look dry, lusterless may have
  a
  
• burning sensation
• Cornea may look cloudy
• Common causes of decreased vision in aging are
  (1) cataract formation, (2) Glaucoma, (3)macular
  degeneration, pg 303
  
• Vocabulary
• Ptosis- drooping upper lid, neuromuscular
  weakness , client has sleepy appearance, pg 333
  
• Blepharitis- Inflammation of the eyelid, staph.
• infection or seborrheic dermatitis of lid edge
  pg 334
  

12

• Hordeolum (stye) pg 334 staph infection of hair
  follicles
  
• Conjunctivitis- pink eye, red-beefy looking at
• periphery but clearer around iris, pg 335
• Cataract formation- lens opacity, most elderly
• have this problem, should be expected by age
• 70,not operated on until ripe
• Glaucoma- increased ocular pressure, men more
• than woman, chronic open-angle glaucoma
• involves gradual loss of peripheral vision
• Macular degeneration- loss of central vision,
• most common cause of blindness