مرجع دانلود پاورپوینت های درسی

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نوع فایل : پاور پوینت
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سمینار تجهیزات چشم پزشکی فهرست مطالب خلاصه ای از آناتومي چشم
تقسیم بندی تجهیزات چشم پزشكي
معرفی تجهیزات
فیلم کوتاهی از عمل کاتاراکت با فیکو
Human Visual System Image formation Exposure
Control Detection Processing Cornea
Lens Iris/pupil
Photoreceptor
sensitivity Retina
Rods
Cones Brain Human Visual System Image formation Exposure
Control Detection Processing Cornea
Lens Iris/pupil
Photoreceptor
sensitivity Retina
Rods
Cones Brain Human Eye Human eye is a complete imaging system. Ear side (Temporal) Nose side (Nasal) Cornea Aqueous Humor Pupil Iris Ciliary Muscle Sclera Fovea Retina Optic Nerve Vitreous Humor Eyelens Choroid Suspensory ligament Image Formation The curved surfaces of the eye focus the image onto the back surface of the eye. Object Image Cornea The outer wall of the eye is formed by the hard, white sclera.
Cornea is the clear portion of the sclera.
2/3 of the refraction takes place at the cornea. Sclera Cornea Iris and Pupil Colored iris controls the size of the opening (pupil) where the light enters.
Pupil determines the amount of light, like the aperture of a camera.
Iris Iris open
Dilated pupil Iris closed
Constricted pupil Pupil Lens Eye lens is made of transparent fibers in a clear membrane.
Suspended by suspensory ligament.
Used as a fine focusing mechanism by the eye; provides 1/3 of eye’s total refracting power.
Non-uniform index of refraction.
Lens Suspensory
Ligament Ciliary muscle Transparent
Fibers Cross section of the eye lens Accommodation The suspensory ligaments attach the lens to the ciliary muscle.
When the muscle contracts, the lens bulges out in the back, decreasing its focal length.
The process by which the lens changes shape to focus is called accommodation. Relaxed muscle
Taut ligaments Distant object Near object Contracted muscle
Slack ligaments Aqueous Humor and Vitreous Humor Transparent gelatinous liquid filling the eye.
Provides nutrients to the cornea and eye lens.
Also helps maintain the eyeball shape with its pressure. Vitreous Humor Aqueous Humor Retina Retina is the photosensitive “detector” for the eye.
Two types of receptors in the retina: rods for low light level, and cones for col...