mdterm

• Visual Field


  What a person sees with one eye, can be divided into four quadrants: upper temporal, lower temporal, upper nasal, and lower nasal

  
• Visual Perception


  Occurs as light rays strike the retina, where they are transformed into nerve impulses, conducted to the brain through the optic nerve, and interpreted. Light must pass through transparent media (cornea, aqueous humor, lens, and vitreous body) before reaching the retina.

  
• Visual Reflexes


  The pupillary light reflex causes pupils to constrict when exposed to bright light. This can be a direct reflex in the eye exposed to light, or an indirect/consensual reflex where exposure to light in one eye results in constriction of the pupil in the opposite eye. These protective reflexes, mediated by the oculomotor nerve, prevent damage to the delicate photoreceptors by excessive light.

  
• PERRLA


  Pupils Equally Round and Reflective to Light Accommodation
• Collecting Subjective Data: The Nursing Health History


  • History of Present Health Concern
  • Personal Health History
  • Past Health History
  • Lifestyle and Health Practices
• Collecting Objective Data: Physical Examination

  1. Prepare the Client

  2. Explain each vision test thoroughly

  3. Position the client comfortably

  4. Explain what you will be doing and answer any questions
• Equipment


  • Snellen or E chart
  • Hand-held Snellen card or near-vision screener
  • Penlight
  • Opaque cards
  • Ophthalmoscope
  • Disposable gloves
• Snellen Chart


  Used to test distant visual acuity, consists of lines of different letters stacked one above the other, the letters are large at the top and decrease in size from top to bottom, the client stands 20 feet from the chart and covers one eye to read each line

  
• E Chart


  Used if the client cannot read or has a handicap that prevents verbal communication, configured like the Snellen chart but the characters are only Es facing in all directions, the client indicates which way the open side of the E faces
• Acuity Test Score


  Recorded as a fraction, the top number is always 20 indicating the distance from the client to the chart, the bottom number refers to the last full line the client could read
• Jaeger Test


  Assesses near vision in clients over 40 by holding a pocket screener or newspaper print 14 inches from the eye, clients with decreased accommodation have to move the card or newspaper further away to see it

  
• Ophthalmoscope


  A hand-held instrument that allows the examiner to view the fundus of the eye by projecting light through a prism that bends the light 90 degrees, has several lenses that can be rotated to affect the focus

  
• Basics of Operation: Ophthalmoscope


  1. Turn the ophthalmoscope on and select the aperture

  2. Ask the client to remove eyeglasses but keep contact lenses

  3. Ask the client to fix their gaze on an object straight ahead and slightly upward

  4. Darken the room to allow pupils to dilate

  5. Hold the ophthalmoscope in your right hand with your index finger on the lens wheel and place it to your right eye if examining the client's right eye, use your left hand and eye if examining the left eye

  
• Do: Begin about 10 to 15 inches from the client at a 15-degree angle, pretend the ophthalmoscope is an extension of your eye and keep focused on the red reflex as you move in closer, then rotate the diopter setting to see the optic disk

  
• Don't: Do not use your right eye to examine the client's left eye or your left eye to examine the client's right eye, do not move the ophthalmoscope around, do not get frustrated as the ophthalmologic examination requires practice

  
• Evaluating Vision


  1. Test distant visual acuity

  2. Test near visual acuity

  3. Test visual fields for gross peripheral vision

  
• Normal Distant Visual Acuity

  20/20 with or without corrective lenses, the client can distinguish what the person with normal vision can distinguish from 20 feet away

  
• Abnormal Distant Visual Acuity (Myopia)

  The second number in the test result is larger than the first (20/40), the higher the second number the poorer the vision, legally blind when vision in the better eye with corrective lenses is 20/20 or less

  
• Cultural Considerations: Visual acuity varies by race, Japanese and Chinese Americans have the poorest corrected visual acuity, followed by African Americans and Hispanics, Native Americans and Caucasians have the best-corrected visual acuity, Eskimos are undergoing an epidemic of myopia