Anatomy of the Eye PDF
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This document provides a detailed description of the anatomy of the human eye. It covers the different layers and parts of the eye, such as the sclera, cornea, iris, pupil, lens, and retina. The document also explains the functions of each part and the process of accommodation.
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# 1- Anatomy of the eye ## The eyeball: ### Layers: - Fibrous - Sclera and Cornea - Vascular - formed of Uvea - Iris, pupil, ciliary body and choroid - Neural - Retina ### Parts: - **Conjuctiva:** - Divided into Bulbar (covering eye) and Palpebral (covering inner lids) - Composed of epi...
# 1- Anatomy of the eye ## The eyeball: ### Layers: - Fibrous - Sclera and Cornea - Vascular - formed of Uvea - Iris, pupil, ciliary body and choroid - Neural - Retina ### Parts: - **Conjuctiva:** - Divided into Bulbar (covering eye) and Palpebral (covering inner lids) - Composed of epithelium and lamina propria - Function: Protection of sclera, cornea and extra-ocular muscles + Blood supply of cornea - **Sclera:** - White part of the eye - Consists of episclera, stroma and lamina fusca - Attachment of extra-ocular muscles - When its near the iris, at the corneal limbus it becomes the cornea - **Cornea:** - Is Transparent, consists of: - Epithelium, Bowman's layer, Stroma, basement (Descemet's) membrane, and endothelium. - Epithelium is Stratified squamous - for regeneration and healing - If stroma, basement membrane or endothelium are damaged - healing by fibrosis - Avascular (transplanted without organ rejection) - Function: refraction of light (slight) - **Iris:** - Colored part - Sphincter pupillae and dilator pupillae muscles, control the size of the pupil - Between the iris and cornea is the _angle of the eye_ - **Pupil:** - The opening in the iris - controls the amount of light entering the eye - Contraction: Miosis - Dilatation: Myadriasis - **Lens:** - Is Avascular - If absent its called Aphakia and if artificial it is pseudophakia - Function: Accommodation (check below) - **Ciliary body:** - Composed of Ciliary processes/epithelium and ciliary muscle - Controls the shape of the lens and so it controls accommodation - Accommodation is the lens' ability to modify shape to focus on nearby objects - Secretes aqueous humor - **Choroid:** - Richly vascular layer - Blood supply of retina and other parts - Is dark and absorbs light so that its focused on the retina - **Retina:** - Composed of 10 layers - Photoreceptors (rods and cones) - Rods: more numerous, sensitive to light, only black and white - night vision - Cones: less numerous, located in macula, less sensitive to light, can see color (red, blue and green) - Day vision - Macula and fovea have highest number of Cones - Optic disc: where optic nerve starts, no rods or cones, is the blind spot.
