L10 Visually Impaired

Question 1

Leading Causes of Blindness

Answer 1

Cataract
Uncorrected Refractive Errors
Glaucoma
AMD (Age-related Mcular Degeneration
Corneal Opacities
Diabetic Retinopathy

Question 2

Nearsightednes

Answer 2

Visual image is focues in front of the retina

Question 3

Farsightedness

Answer 3

Visual image is focues behind the retina

Question 4

Astigmatism

Answer 4

Astigmatic cornea distorts the focal point of the light in front of and/or behind the retina

Question 5

Glaucome

Answer 5

Drainage channel is blocked - Pressure buildup in vitreous cavity causing changes in optic nerve

Question 6

Visually Impaired: Home Considerations

Answer 6

• Remove hazards: worn carpet, electrical cords, large furniture from
  pathways
• Low vision: increase lighting, under cabinet lighting in kitchen, light
  switches near by bed, regularly spaced
• Add contrast: light/dark objects, colored tape around edges of
  steps/ramps

Question 7

Visually Impaired: Electronic Mobility Aids

Answer 7

• UltraCane: emits ultrasound to detect objects, short
  (2m) and long (4m ) range
• GuideCane: array of ultrasonic sensors and rolls on
  wheels
• iGlasses: used with an eye dog or cane; detect objects
  at head/chest level
• Navbelt: prototype – 8 ultrasonic systems on a belt
• MiniGuide:hand held device that emits an ultrasonic
  beam and provides vibratory or auditory feedback