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Visual Perception Kit. Carolina $117.00. Time Required. Approximately 8 minutes per station With 10 stations that will require 80 minutes Additional time is required to answer assessment and review questions. Preparation. Prior to lab review eye structure and function
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Visual Perception Kit Carolina $117.00
Time Required • Approximately 8 minutes per station • With 10 stations that will require 80 minutes • Additional time is required to answer assessment and review questions
Preparation • Prior to lab review eye structure and function • Lab is designed so that 10 stations can be set up and instructions for each station are included • Pre-lab set-up • Wrap white paper lengthwise around pencils • Set up “Depth Perception Tester” on level surface
Pre-lab Activities • Demonstrate visual acuity test and benefit of corrective lenses • Have students predict and then identify their dominant eye • Look at an object ~3m away • With both eyes open, hold your thumb arms’ length and “cover” the object with your thumb • Close right eye • Results – if your thumb appears to move to the right, the right eye is dominant. If your thumb did not seem to move, your left eyes dominant.
Activities Included • Visual Acuity • Astigmatism and Blind Spot • Visual Mapping • Color Vision • Depth Perception • Accommodation • Near Point • Peripheral Vision • Afterimages • Illusions
Visual Acuity • Uses Snellen chart (eye chart) to determine emmetropia (normal vision), hyperopia (farsightedness), myopia ( nearsightedness) • Astigmatism and Blind Spot • Astigamatism- irregular shape of cornea or lens • Results in blurred or distorted images • Blind spot- area on retina with no photoreceptors • Visual Mapping • Used to determine the size of the fovea centralis • Fovea centralis- area of eye with greatest visual acuity, contains more cone cells than any other region of eye
Color Vision • Cones- cells in retina which see color • Rods- cells in retina which see dim light and shades of gray • Different cones work together to see different colors • Depth Perception • Ability to judge the relative distance between objects in three dimensions • Done using monocular vision(seeing with one eye) and binocular vision(seeing with two eyes) • Accommodation • Combination of reflex actions by which the lens of the eye changes to keep the focal length constant • If works normally= emmetropia • If eye ball is deeper than normal = myopia • If eye ball is not deep enough= hyperopia
Near Point • Minimum distance at which the eye can focus on an object • Peripheral Vision • Ability to see things which fall outside the direct line of vision • Used in the detection of motion • Afterimages • Optical illusion that occurs when looking away after staring intently at certain images or colors • Illusions • Deceptive, self-contradictory, or misleading images • Visual tricks which take place in the brain rather than the eye
Today… • Get in groups of 3 • We will test our • Depth Perception • Peripheral Vision • Illusions