Visual Communication involves the eye registering changes in the immediate environment. COMMUNICATION: HSC BIOLOGY OPTION. The outer eye:. CONJUNCTIVA. A thin, transparent mucous membrane that covers the sclera (the white of the eye). It lines the inner surfaces of the eyelids. - PowerPoint PPT Presentation
COMMUNICATION: HSC BIOLOGY OPTION
COMMUNICATION:HSC BIOLOGY OPTIONVisual Communication involves the eye registering changes in the immediate environment
The outer eye:
A thin, transparent mucous membrane that covers the sclera (the white of the eye). It lines the inner surfaces of the eyelids. Tiny secretory glands in the produce tear film that lubricates and protects the eye while it moves in its socket and helps to keep it clean.It covers and protects the surface of the corneaCORNEATransparent front window through which light enters the eyeball.
SCLERAThe external layer of the eye continuous with the cornea.The white of the eye.
Tough, non elastic tissue protects the delicate inner layers of the eye.It helps to maintain the shape of the eyeball. Attachment for the external muscles of the eye which enable the eyeball to move in the socket. The inner eye:
LENS -Biconcave discRefracts light rays & focuses them on the retina.
CILIARY BODY- Holds the lens in place yet allows flexible movements of the lens.Secretes the aqueous humour
Coloured part of the eyeA ring of muscle with a hole in the middle (the pupil). Controls size of pupil & amount of light entering eye. In dim light pupil dilates to let more light in.In bright light the iris tightens and the pupil contracts.RETINA
The inner layer of the eye.
Contains photoreceptors for vision
Highly specialised rod & cone cells respond to light, converting light energy into nerve impulses.Aqueous & Vitreous HumourTransparent watery fluidProvides nutrients for the lens & cornea.Clear jelly-like substanceRefracts lightHelps maintain the shape of the eyeball
The middle layer of the eye which extends into the irisA sheet of blood vessels that carries oxygen & nutrients to the eye and remove carbon dioxide and wastesPosteriorly it is black which prevents light in the eye from scattering.
Transfers the visual signals to the brain for processing.OPTIC NERVE