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12 Cards in this Set
- Front
- Back
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Cone Cells |
One of the photoreceptors in the retina of the eye that is responsible for daylight and color vision |
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Rod Cells |
(Help see in dark places) The rods are most sensitive to light and dark changes, shape and movement and contain only one type of light-sensitive pigment. Rods are not good for color vision. In a dim room, however, we use mainly our rods |
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Astigmatism, Nearsighted, Farsighted |
Nearsightedness (myopia) is the light coming into the eye is not focused onto the retina, making it hard to see objects far away. Farsightedness (hyperopia) is the opposite of myopia, and is usually caused by shortening of the eyeball. Astigmatism is an imperfection of the cornea preventing part of it from focusing light onto the retina. The result is a blurred area within an otherwise clear image. |
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Types and causes of blindness |
Night blind: Can't see in the dark, often havin to do with your rob cells. Colour Blind: Can't see colours, often having to do with cone cells.
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Blind Spot: |
the small circular area at the back of the retina where the optic nerve enters the eyeball and which is devoid of rods and cones and is not sensitive to light |
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Telescope types: |
Compound light microscope : uses 2 convex lenses to magnify small objects
Refracting telescope: Convex lens to collect an focus light from a distant object, and a convex eyepiece to magnify the image. Glass lenses absorb some of the light and are expensive. Reflecting telescope: Uses a concave mirror, a plane mirror, and a convex lens. Most large telescopes are reflecting telescopes. Convex = Magnifies |
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Binoculars: |
2 mounted refracted telescopes mounted side by side. Prisms in the binoculars are used to reflect light back and forth. |
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Camera and eye differences |
Eyelid = Lens cap Iris = Diaphram Retina = CCD Rods/Cornea = Pixels |
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Laser Lights and laser Surgery |
Laser light is a light of only 1 wavelength. Can travel great distances without spreading out. Lasers can be used in place of scalpels in surgery. Laser Surgery: Remove cateracts, Reattach retina, reshape cornea. |
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Microscopes: |
A microscope magnifies small objects by forming an enlarged image of the object. A compound light microscope uses two convex lenses. |
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Optical Fibres: |
Transparent glass fibres that can transmit light from one place to another. Transmit light by using total infernal reflection. (when light strikes a boundary between two materials and is totally reflected) They are used for medical procedures, and telecommunications. |
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Total infernal reflection: |
When light strikes a boundary between two materials and is totally reflected. |
