Vision 1/2 Flashcards
1
Q
Sclera
A
White of the eye, opaque, fibrough outer sheather that offers protection
2
Q
Cornea
A
- Made of similar fiber, dome-shaped lens that is transparent, which allows light to pass through
3
Q
Iris
A
- Determines your eye colour
- Controls diamtere of the pupil, permiting for optimal amount of light to enter the eye
4
Q
Lens
A
- Responsible for most of the remaining focusing ability of te eye after the cornea.
- The curvature can be altered such that imates are brought into focus based on how far away they are.
- This process is called accomodation where the lens will get rounder to produce a clear image of a close object; when the lens elongates, the your eye is producing image of a far away object.
5
Q
Hyperopia (farsightedness)
A
If there is a refraction error, the light rays may be focused hind or front of the retina, meaning the image will be out of focus
- One can see distant objects with relative ease, but closer objects appear blurry because the light is focused to a hypothetical location behind the retina.
- Tend to have a slightly shorter eye length
- Less curved lense
6
Q
Myopia
(nearsightedness)
A
- One can usually see closer objects wit hease, but distant objects appear blurry because the light is focused to a hypothetical location in front of the retina
- tend to have a slightly longer eye length
- More curved lens
7
Q
Retina
A
- Found at the back of the eye where light is converted into electrical signals.
8
Q
Photoreceptors
A
- The first layer of the eye closest to the very back
- Detects light and pass this information on to the next layer
- Note the strange order of events: light must first pass through ganglion cells, horizontal cells, amacrine cells, and bipolar cells before striking the photoreceptors that start the whole process.
9
Q
Bipolar cells
A
- Section after the photoreceptor
10
Q
Ganglion cells
A
- Relay the singlas onto the brain
11
Q
Rods
A
- Responsible for low light vision because they they contain photopigment sensitive to light.
- Total loss would produce night blindness
- Provides no colour information and offer poor visiual acuity
- Useful in the peripheral vision.
12
Q
Cones
A
- Responsible for photopic vision and contails photopigments that are less sensitive to light.
- There are 3 different types of cones each to maximize a certain wavelength of light (blue, red and green)
- Referted to as chromatic because it grants us the ability to percieve colour.
13
Q
Fovea
A
- Exclusively populated with cones, thus achieving maximal visual acuity.
- Rods are absent from the fovea but densely packed across most of the retina, especially around the periphery of the fovea.
14
Q
Optic disk
A
- No photorecpetors at all
- Instead made up of axons from the ganglion cells that are needed to carry signasl from the retina to the brain.
- Refered to as the blind spot, where our vision field foes entirely uncaptured.
15
Q
Dark adaptation
A
- th