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Human Body System #5

Unit 2 Test Study Stack

The automatic adjustment of the eye for seeing at different distances affected chiefly by changes in the convexity of the crystalline lens. Accommodation
A defect of an optical system (as a lens) causing rays from a point to fail to meet in a focal point resulting in a blurred and imperfect image. Astigmatism
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. Blind Spot
Any of the conical photosensitive receptor cells of the vertebrate retina that function in color vision. Cone
The transparent part of the coat of the eyeball that covers the iris and pupil and admits light to the interior. Cornea
The ability to judge the distance of objects and the spatial relationship of objects at different distances.` Depth Perception
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. Hyperopia
The opaque muscular contractile diaphragm that is suspended in the aqueous humor in front of the lens of the eyeexcludes the entrance of light except through the pupil and a colored anterior surface which determines the color of the eyes. Iris
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. Lens
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 -- called also nearsightedness. Myopia
Either of the pair of sensory nerves that comprise the second pair of cranial nerves form an optic chiasma before passing to the eye and spreading over the anterior surface of the retina, and conduct visual stimuli to the brain. Optic Nerve
The opening in the iris, which admits light into the interior of the vertebrate eye; muscles in the iris regulate its size. Pupil
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. Refraction
Lines most of the posterior chamber of the vertebrate eye functions as the immediate instrument of vision by receiving the image formed by the lens and converting it into chemical and nervous signals which reach the brain by way of the optic nerve. Retina
Any of the long rod-shaped photosensitive receptors in the retina responsive to faint light. Rod
Created by: maseyann