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23 Cards in this Set
- Front
- Back
Sclera |
Outer covering of eye. White of the eye. Protects inner layers. |
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Cornea |
Transparent part that protects the eye. Refracts light towards the pupil. |
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Aqueous Humor |
Watery liquid that protects the eye and and supplies cornea with nutrients. |
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Choroid layer |
Middle layer of tissue that contains blood vessels. |
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Iris |
Regulates the amount of light entering the eye. |
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Retina |
Inner layer of tissue at the back of the eye containing photoreceptors. |
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Rods |
Photoreceptors that operate in dim light. In black and white. |
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Cones |
Photoreceptors that operate in bright light. Identify colour. |
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Vitreous humor |
Maintains shape of eyeball. |
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Pupil |
The opening in the iris that allows light into the eye |
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Lens |
Focuses the image on the retina. Disk. |
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Fovea Centralis |
Most light sensitive part of retina. Contains only cones. |
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Blind spot |
Where the optic nerve connects to retina |
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Rhodopsin |
Pigment found in rods of eye that releases neurotransmitters. Bright light: breaks down faster than can be restored. |
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Colours that cones are sensitive to and colour blindness |
Red blue green. Colour blindness is red and green not working. |
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Accommodation |
Adjustments made by lens and pupil to identify near and distant objects. Close object: ciliary muscles contract, ligaments go slack, lens becomes thicker. Far object: ciliary muscles relax, ligaments are stretched, lens thins. |
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Why do people need reading glasses as they age? |
Layers of transparent protein covering lens becomes increase with age, making the lens harden. It loses flexibility. |
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Glaucoma |
Build up of aqueous humor increases pressure in eyeball when ducts don't drain excess. Retina cells begin to slowly die causing gradual loss of sight. |
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Cataract |
When lens or cornea becomes opaque, preventing light from passing through |
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Astigmatism |
Vision defect caused by abnormal curving of the lens or cornea |
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Nearsightedness (myopia) |
Eyeball is too long, can focus near not far, image is focused in front of retina, glasses are concave. |
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Farsightedness (hyperopia) |
Eyeball is too short, image is focused behind retina, can see far but not near, glasses are convex. |
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Order that light enters eye |
Cornea, aqueous humor, pupil, lens, vitreous humor, retina |