Chap 17, The Eye, Vocabulary Flashcards
accommodation
Normal adjustment of the eye to focus on objects from far to near. The ciliary body adjusts the lens (rounding it) and the pupil constricts. When the eye focuses from near to far, the ciliary body flattens the lens and the pupil dilates.
anterior chamber
Area behind the cornea and in front of the lens and iris. It contains aqueous humor.
aqueous humor
Fluid produced by the ciliary body and found in the anterior chamber. A humor is any body fluid, including blood and lymph.
biconvex
Consisting of two surfaces that are rounded, elevated, and curved evenly, like part of a sphere. The lens of the eye is a biconvex body.
choroid
Middle, vascular layer of the eye, between the retina and the sclera.
ciliary body
Structure surrounding the lens that connects the choroid and iris. It contains ciliary muscles, which control the shape of the lens, and it secretes aqueous humor.
cone
Photoreceptor cell in the retina that transforms light energy into a nerve impulse. Cones are responsible for color and central vision.
conjunctiva
Delicate membrane lining the undersurface of the eyelids and covering the anterior eyeball.
cornea
Fibrous transparent layer of clear tissue that extends over the anterior portion of the eyeball.
fovea centralis
Tiny pit or depression in the retina that is the region of clearest vision.
fundus of the eye
Large posterior, inner part of the eye that is visualized with an ophthalmoscope.
iris
Pigmented (colored) layer that opens and closes to allow more or less light into the eye. The central opening of the iris is the pupil.
lens
Transparent, biconvex body behind the pupil of the eye. It bends (refracts) light rays to ring them into focus on the retina.
macula
Yellowish region on the retina lateral to and slightly below the optic disc; contains the fovea centralis, which is the area of clearest vision.
optic chiasm
Point at which optic nerve fibers cross in the brain.