special senses: visual tests and experiments Flashcards
• Accommodation
o The ability for an eye to focus differentially for objects of near vision (less than 6m, or 20 feet)
• Real image
o Reversed form left to right
o Inverted
o Smaller than object
• Emmetropic eye/ normal eye
o Able to accommodate properly
• Near point of accommodation
o Test for lens elasticity
• Vision acuity
o Sharpness of vision
o Teste with Snellen eye chart
• Depth perception or three-dimenional vision
o When the primary visual cortex fuses the slightly different images
• Lens selection disc
o Set of lens mounted on a rotating disc on a opthalmoscope
• Rheostat control
o A mirror that reflects the light so that the eye interior can be illuminated in opthalmoscope
• Myopia
o Nearsightedness
o Individuals in whom the image normally focuses in front of the retina
• Hyperopia
o Farsightedness
o The image focuses behind the retina
• Astigmatism
o Irregularities in the curvatures of the lens and or the cornea that lead to blurred vision
• Presbyopia
o Old vision
o When the elasticity of the lens dramatically decreases with age
