Karteikarten
The Eye
Karten in diesem Stapel (11)
- 1Near PointThe closest point the eye can focus on. For the average human adult, that's around 25cm
- 2Far PointThe furthest distance the eye can focus on comfortable. For normally-sighted people, this is infinity
- 3Short-sightedPeople that are short-sighted can't focus on distant objects. Their focal point is in front of the retina. Short sight can happen due to things like the cornea/lens being to powerful, the eyeball being too long or the ciliary muscles not being able to contract enough to change the shape of the lens to focus the light on the retina.
- 4Long-sightedLong-sighted people can't focus clearly on near objects. Their focal point is further away than normal (drawn behind the retina).Long sight can be caused because the cornea/lens are too weak, the eyeball is too short or the ciliary muscles might not be able to relax enough to change the shape of the lens. Lots of people become long-sighted as they grow because the lens gets stiffer or the ciliary muscles get weaker.
- 5CorneaA transparent 'window' that has a convex shape and does some of the focusing of light rays alongside the lens
- 6IrisThe Coloured part of the eye made from that control the size of the pupil
- 7LensFocuses light, alongside the cornea, onto the retina and can change its shape to focus the image by changing shape
- 8Light-sensitive CellsRods and Cones that cover the retina and detect light in order to send signals to the brain via the optic nerve
- 9PupilA hole in the middle of the iris that controls the amount of light entering the eye
- 10RetinaBack of the eye, where the image is focused onto so that the rods and cones can create image signals that are then sent to the optic nerve
- 11Ciliary MusclesThese control the lens; they contract and relax to change the shape of the lens- contract to fatten and adopt more spherical shape, and relax to thin and adopt a flatter shape.
Informationen
- Beschreibung
- Science Karteikarten am The Eye, erstellt von A.M am 04/05/2013.
- Erstellt von
- A.M
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- 25
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