VISION the sense we rely on most often
Photoreceptors in the eye are sensitive to wavelengths of light energy called the visible spectrum
Structures of the Eye
vitreous
Structures of the Eye iris vitreous
Structures of the Eye cornea vitreous iris
Structures of the Eye pupil vitreous iris cornea
Structures of the Eye lens vitreous iris cornea pupil
Structures of the Eye retina vitreous iris cornea pupillens
Structures of the Eye Optic nerve vitreous iris cornea pupil lens retina
Structures of the Eye
Function of Eye Structures
Lens – focuses the image on the retina Iris – pigmented muscle that give the eye its color and regulates the size of the pupil Pupil -- not a structure, but an opening in the iris Cornea – transparent portion of the sclera through which light enters
Function of Eye Structures Retina – layer containing photoreceptors that transduce light energy into a nerve impulse Rods – photoreceptors that are unable to detect color, but work well in low light Cones – photoreceptors that detect color in bright light but not in low light
Location of Rods and Cones CC
Function of Eye Structures The macula is located roughly in the center of the retina. It is a small and highly sensitive part of the retina responsible for detailed central vision. The fovea is the very center of the macula.
Vision Problems Glaucoma – pressure build up inside the eye causes damage (a leading cause of blindness around the world) Color Blindness – genetic deficiency in the cones, most common form is red/green color blindness (inability to distinguish between reds and greens) Cataracts – clouding of the lens
Vision Defects in Focusing Myopia = nearsighted due to an elongated eyeball Requires a concave lens to correct
Vision Defects in Focusing Hyperopia = farsighted due to a shortened eyeball Presbyopia = farsighted due to aging Farsightedness requires a convex lens to correct
Vision Defect in Focusing Astigmatism = due to a misshapen cornea, part of the image is focused and part is not Requires a non-symmetrical lens to correct