One Pair of Eyes© An Eye Health and Safety Program Funded by the Ohio Department of Health Bureau of Child and Family Health Services Save Our Sight Program Supported by Prevent Blindness Ohio and Nationwide Children’s Hospital 1 1

You are here… To value and preserve your one pair of eyes. To learn the right eye protection to use in a given situation. To find out what to do if you get an eye injury.

Basic Anatomy If you haven’t already seen the flash player tour of the human eye, please take a few moments to explore it now: http://www.preventblindness.org/vlc/how_we_see.htm Click your mouse on each part for a brief explanation. (When you’re finished, exit or click “back” to return here.)  Seriously….the rest of the presentation will make more sense if you watch it first. (For clickable links to websites with more info on sight and eye health, please see Student Resources slides that follow this presentation.) 3

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Rods and cones are the cells that process light. More Anatomy Rods and cones are the cells that process light. There are about 120 million rods and 7 million cones in each of your eyes. Rods are important for night vision and help us see black, white and shades of grey. Birds of prey have about 5 x the number of rods than humans per square millimeter of retina tissue. Cones are important for sharpness and help us see color. You have three kinds of cones, those that perceive red, green, and blue. 5

Got Cones? Color blindness, also known as color vision deficiency, is the inability to distinguish colors and shades or to recognize them at all. It occurs when the color-sensing cones of the retina are absent or do not function properly. Normal Color Vision Simulated Color Blind Vision 6

Wouldn’t you know it? About 8 percent of males and 1 percent of females are color-blind to some degree. What if this  were a SINGLE flashing light? How would you know if it was red or yellow? ? 7

Optical Illusions Why do we see gray dots when we know there aren’t any, or see movement when we know something is actually completely still? 8

The horizontal lines are indeed straight. Our eyes process the signals and transmit that interpretation to the brain. When the input doesn’t make perfect sense, the brain “fills in the blanks” and sometimes sees things not-quite as they are. The horizontal lines are indeed straight. To see an interactive version of this illusion, go to: http://www.preventblindness.org/wiseabouteyes/lessons/eye/ 9

The brain has learned that a progression of large to small indicates distance. ©2004 A. Kitoka Most people see the dots as curving (like 3 cylinders). Many people actually experience this as rotating cylinders. The progression of shapes suggests movement to the brain. 10

“Eye Safety: It Only Takes a Second, but Lasts a Lifetime" 1. Click below to watch this short video on how to prevent eye injuries in school science and vocational practicum classes: “Eye Safety: It Only Takes a Second, but Lasts a Lifetime" View Video 2. Low Vision Simulation: Go to the Arizona Center for the Blind and Visually Impaired Inc.’s webpage to see what your world might look like if your eyes were damaged: http://www.acbvi.org/albums/Vision/index.html 11

Precious Sight What would you miss most if you could never see again? 12

Next... What's Chemical Injuries to the Eyes Impact Injuries to the Eyes Dust Dangers Heat Injuries to the Eyes Vocational Eye Safety (lab & shop) Light Injuries to the Eyes Eye Infections A special word about Fireworks 13