| Term | Definition |
|---|
| sclera | white, outer covering of the eye that supports & protects the eye's inner layers |
| cornea | transparent part of the sclera that protects the eye & refracts light toward the pupil of the eye |
| aqueous humour | watery liquid that protects the lens of the eye and supplies the cornea with nutrients |
| conjunctiva | mucous membrane, covers the front of the eye & lines the inner surface of the eyelid |
| lacrimal gland | gland located in the upper outer region bove the eyeball that secretes tears |
| lysozyme | an enzyme that destroys bacteria by dissolving their cell walls. found in mucus, tears, and saliva |
| vitreous humour | the clear colorless transparent jelly that fills the posterior chamber of the eyeball. Maintains shape of eyeball & permits light transmission to the retina |
| retina | innermost layer of tissue at the back of the eye containing photoreceptors. It is continuous with the optic nerve. |
| optic disk | the point where the optic nerve enters the retina. Also known as the blind spot (no photoreceptors here). |
| choroid layer | middle layer of tissue in the eye that contains blood vessels & dark pigments that absorb light to stop reflection. |
| tapetum lucidum | part of the choroid layer in the cow eye that appears iridescent. It reflects light on to the retina (useful at night). Not present in human eye. |
| iris | opaque disk of tissue(coloured) surrounding the pupil that regulates amount of light entering the eye |
| pupil | the opening in the iris through which light enters eye |
| lens | transparent structure behind the pupil that bends and focuses light rays on the retina |
| suspensory ligaments | ring of fibres that radiate from the edge of the lens & attach it to the ciliary body. Help change the shape of the lens. |
| ciliary muscles | muscles attached to the ligaments, which relax or contract and alter the shape of the lens |
| rods | photoreceptors that operate in dim light to detect light in black & white |
| cones | photoreceptors that operate in bright light to identify colour |
| fovea centralis | area at centre of retina where cones are most dense and vision is sharpest |
Combine with other sets
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