PLTW: HBS - 2.4, 2.4.3 Put Yourself in Someone Else's Eyes (Key Terms), 2.4.1- Exploring the Anatomy of the Eye, 2.4.2- Visual Perception
Aqueous Humor
A clear, watery fluid that fills the space between the cornea and iris.
Myopia
A condition in which the visual images come to a focus in front of the retina of the eye because of defects in the refractive media of the eye or of abnormal length of the eyeball resulting especially in defective vision of distant objects -- called also nearsightedness.
Hyperopia
A condition in which visual images come to a focus behind the retina of the eye and vision is better for distant than for near objects - called also farsightedness.
Lens
A curved piece of glass or plastic used singly or combined in eyeglasses or an optical instrument (as a microscope) for forming an image by focusing rays of light.
Vitreous Humor
A thick, gelatinous fluid found in the posterior segment of the eye (between the lens and the retina).
tapetum
Allows animals who are active in low light to have the light reflect off the back of the eye and bounce around inside the eyeball.
Glaucoma
An abnormal condition of elevated pressure within an eye.
Cataracts
Clouding of the lens of the eye.
Retinitis Pigmentosa
Genetic disease of light sensitive cells in retina - progressive night blindness, peripheral vision, total blindness
Myopia (Near Sightedness)
Lens focuses object in front of retina - can see near objects well but not not far away objects
Cone
Localized photosensitive receptor cells that function in color vision and detail.
Astigmatism
Misshapen lens resulting in a blurred and imperfect image.
Rod
Photosensitive receptors found in much of the retina responsible for seeing motion, black/white.
Iris
Pigmented part of the eye that surrounds the pupil and determines how much light to let in to the eye.
Photoreceptors
Rods and Cones
red-green colorblindness
Sex linked trait that usually results in males who are dependent on only their blue cones, as the others do not function.
Depth Perception
The ability to judge the distance of objects and the spatial relationship of objects at different distances.
Accommodation
The automatic adjustment of the eye for seeing at different distances affected chiefly by changes in the convexity of the crystalline lens.
Optic Nerve
The connection between the eye itself and the brain.
Refraction
The deflection from a straight path undergone by a light ray or a wave of energy in passing obliquely from one medium (as air) into another (as water or glass) in which its velocity is different.
Pupil
The opening in the iris, which admits light into the interior of the vertebrate eye; muscles in the iris regulate its size.
six muscles per eye
The reason that humans can roll their eyes and cows can't.
Retina
The sensory membrane that lines most of the large posterior chamber of the vertebrate eye and functions as the immediate instrument of vision.
Blind Spot
The small circular area in the retina where the optic nerve enters the eye that is devoid of rods and cones and is insensitive to light.
Cornea
The transparent part of the coat of the eyeball that covers the iris and pupil and admits light to the interior.
ciliary muscles
These are used to change the shape of the lens.
detached retina
This could happen if the pressure inside the eye was not high enough to keep the retina in place.
optomitrist
Trained to do vision tests and diagnose eye issues especially those needing corrective lenses. Can not do surgery.
optician
Trained to verify and fit eyeglasses
convergent
Type of lens used to correct hyperopia
divergent
Type of lens used to correct myopia
Glaucoma
a buildup of internal eye pressure (intraocular pressure) - can damage the optic nerve, blurred vision on edges or blindness
Aqueous Humor
a clear fluid that helps the cornea keep its rounded shape
Cornea
a tough, clear covering over the iris and pupil that helps protect the eye. Light bends as it passes through
Color Perception Deficiency
any of the three types (red, blue, green) of cones that don't work
Cataracts
as one ages, proteins in the lens clump together and start to cloud the lens - surgery to replace lens
Fovea Centralis
center of macula and is the region of the greatest visual acuity
Lens
clear, flexible structure that makes an image on the eye's retina
cone cells
concentrated at the center of the retina in an area called macula lutea
Astigmatism
condition in which the cornea or lens is irregularly shaped
macula
contains no rods and is responsible for sharp, colorful images
Optical Illusions
deceptive, self-contradictory, and misleading images
Macular Degeneration
degeneration of the macula (part of the retina possible for vision - central vision affected (not really seeing things) spot in the middle of vision they can't see
Hyperopia
farsighted eye is too short glasses (+) prescription convergent (convex)
Cones
function in bright light and provide sharp, colorful daylight images
Rods
function in dim light and perceive shades of gray
Color Blindness
lack of certain type of cone - certain colors are hard to differentiate
Retina
layer of light-sensitive cells at the back of the eye. It detects images focused by the cornea and lens. It's connected to the brain by the optic nerve.
Hyperopia (far sighted)
lens focuses object beyond/behind the retina - can see far away objects well, but not near objects
Near Point
minimum distance which the eye can focus
Iris
muscle that controls how much light enters the eye
Myopia
nearsighted eye is too long glasses (-) prescription divergent (concave)
blind spot
no photorecepters
Emmetropia
normal eye vision
Afterimage
optical illusion that occurs when looking away after staring intently at certain images or colors
Tapetum
shiny material behind retina, not found in humans
Things that effect optical illusions
surrounding objects, intense colors, distortions, preconceptions
Depth Perception
the ability to judge the relative distance between objects in three dimensions
Peripheral Vision
the ability to see things that fall outside the direct line of vision. Controlled by rods
Visual Activity
the amount of detail the eye can distinguish
Optic Nerve
the bundle of nerve fibers that carry information from the retina to the brain
Accommodation
the combination of reflexive actions by which the lens of the eye changes to keep the focal length constant
Pupil
the dark circle in the center of your iris. It's a hole that lets light into the inner eye
blind spot
the point at which the optic nerve leaves the eye, light cannot be stimulated
sclera
the toughest part of the eye, also known as the "whites" of the eye.
red, green, blue
the types of cones in humans
Vitreous Humor
thick, clear jelly that gives the eyeball it's shape
Scelra
thick, white outer covering of eyeball