Visual Disorders - Cogs & Psych 160D/Bio N165

A set of vocabulary flashcards based on visual disorders and the functioning of the visual system.

Illusory Contours

Visual illusions that create the perception of an edge without a luminance or color change.

Visual Pathways

The paths through which visual information is processed, starting from the retina to the primary visual cortex.

Fovea

The central region of the retina responsible for sharp central vision, crucial for tasks like reading and driving.

Photoreceptor Cells

Specialized cells in the retina that convert light into electrical signals, including rods and cones.

Rods

Type of photoreceptor cells that are sensitive to low light levels and are responsible for scotopic (night) vision.

Cones

Type of photoreceptor cells that operate in bright light and are responsible for color vision and visual acuity.

Cataract

A clouding of the lens that blocks light from reaching the retina, commonly associated with aging.

Blind Spot

The area in the visual field that corresponds to the optic disc, where there are no photoreceptor cells.

Univariance Principle

The principle stating that a single type of photoreceptor cannot distinguish between light intensity and wavelength.

Troxler Effect

The phenomenon where a fixed gaze on a stationary image causes it to fade from view.

Achromatopsia

A condition resulting in complete color blindness due to the non-functionality of cone photoreceptors.

Prosopagnosia

A cognitive disorder characterized by the inability to recognize familiar faces.

Tetrachromacy

The condition of possessing four types of cone cells for color discrimination, allowing for a broader range of color perception.

Cerebral Achromatopsia

Loss of color perception caused by cortical lesions, affecting regions like V4.

Simultanagnosia

A condition where a person can see multiple objects but can focus on only one at a time.

Bitemporal Hemianopsia

Vision loss in the outer half of the visual field in both eyes, typically caused by a tumor at the optic chiasm.

Midget Retinal Ganglion Cells

Cells that connect to the parvocellular pathway, characterized by small dendritic trees and slow conduction velocity.

Parasol Retinal Ganglion Cells

Large cells that are fast-conducting and respond to motion, part of the magnocellular pathway.

Melanopsin

A photopigment found in a type of retinal ganglion cell that contributes to non-image-forming visual functions.

Visual Agnosia

A disorder where patients cannot recognize objects, despite having intact vision, due to damage in specific brain areas.

Akinetopsia

A condition characterized by the inability to perceive motion, often described as seeing the world in snapshots.