10 - Vision: From Eye to Brain Flashcards
Visual acuity
Sharpness of vision
Vision field
The whole area that you can see without moving your head or eyes
Photoreceptors
Neural cells in the retina that respond to light
Lateral inhibition
The phenomenon by which interconnected neurons inhibit their neighbors, producing contrast at the edges of regions
Quantum (pl. quanta)
A unit of radiant energy
Wavelength
The length between two peaks in a repeated stimulus such as a wave, light, or sound
Photon
A quantum of light energy
Cornea
The transparent outer layer of the eye, whose curvature is fixed. It bends light rays and is primarily responsible for forming the image on the retina
Lens
A structure in the eye that helps focus an image on the retina
Refraction
The bending of light rays by a change in the density of a medium, such as the cornea and the lens of the eyes
Ciliary muscle
One of the muscles that controls the shape of the lens inside the eye, focusing an image on the retina
Accommodation
The process of focusing by the ciliary muscles and the lens to form a sharp image on the retina
Pupil
The aperture, formed by the iris, that allows light to enter the eye
Iris
The circular structure of the eye that provides an opening to form the pupil
Extraocular muscle
One of the muscles attached to the eyeball that control its position and movements
Retina
The receptive surface inside the eye that contains photoreceptors and other neurons
Rods
A class of light-sensitive receptor cells (photoreceptors) in the retina that are most active at low levels of light
Cones
A class of photoreceptor cells in the retina that are responsible for color vision
Bipolar cells
A class of interneurons of the retina that receive information from rods and cones and pass the information to retinal ganglion cells
Ganglion cells
A glass of cells in the retina whose axons form the optic nerve
Optic nerve
Cranial nerve II; The collection of ganglion cell axons that extend from the retina to the optic chiasm
Horizontal cells
Specialized retinal cells that contact both the receptor cells and the bipolar cells
Amacrine cells
Specialized retinal cells that contact both the bipolar cells and the ganglion cells, and are especially significant in inhibitory interactions within the retina
Scotopic system
A system in the retina that operates at low levels of light and involves the rods
Photopic system
A system in the retina that operates at high levels of light, shows sensitivity to color, and involves the cones
Rhodopsin
The photopigment in rods that responds to light