Transcript Anatomy of the Eye

Anatomy of the Eye
By: Kaitlyn Stevens, Nicole Morgan, Cayla Campbell, Blake Rogers, Megan Simpson
Parts of the Eye
http://www.medicinenet.com/imagecollection/eye_anatomy_detail_picture/picture.htm
Parts of the Eye Explained
 Retina- light-sensitive inner lining of the back of the eye
 Cornea- clear front surface of eye, part of the eye that primarily focuses light
 Iris- functions like diaphragm of a camera, controls amount of light reaching the back of
the eye by adjusting the size of the pupil
 Anterior Chamber- space between cornea and iris
 Lens- located directly behind the pupil and focuses light
 Posterior Chamber- region behind the iris
Parts of Eye Continued
 Ciliary body- controls ciliary muscle, controls shape of lens and ciliary epithelium
 Aqueous humor- slightly alkaline liquid that occupies the anterior and posterior chambers
of the eye
 Suspensory ligaments- ligament that supports a body part
 Vitreous humor- transparent, colorless, gelatinous mass that fills the space between the
lens of the eye and the retina lining the back of the eye
Parts of Eye Continued
 Choroid coat- vascular layer of the eye lying between the retina and the sclera
 Sclera- “white part of eye”, fibrous, protective, outer layer of eye made of collagen and
elastic fibers
 Optic disc- raised disk on retina at point of entry of optic nerve, lacks visual receptors and
creates a blind spot
Function of Eyelid
 Eyelids protect eye from dirt, dust, bright
light, and foreign matter
 Eyelids also help spread tears over
surface of eye
 Lacrimal Apparatus produces tears
http://marineyes.com/anatomy/eyelid.html
Structures of the eye
 Light rays enter the eye through the cornea, the clear front “window” of the eye. The
cornea’s refractive power bends the light rays in such a way that they pass freely through
the pupil the opening in the center of the iris through which light enters the eye.
Function of Extrinsic Eye Muscles
 Some of the fastest contracting and most precisely controlled skeletal muscles in the
human body
 Function as Agonist & Antagonists pairs to move the eyeball
Accommodation
 Lens helps the eye automatically focus on near and approaching objects, like an autofocus camera lens.
Refraction
 change in direction of propagation of any wave as a result of its traveling at different
speeds at different points along the wave front.
 •measurement of the focusing characteristics of an eye or eyes.
Refractive Disorders
 Eyeglass lenses correct refractive errors by focusing light directly on the retina. The type of
lens depends on the type and severity of the refractive error.
 The strength of a lens (i.e., its refractive power) is measured in optical units called diopters.
This measurement indicates how much refractive power the lens must have to focus
images directly on the retina. The higher the diopter, the stronger the lens.
Structure of the Retina
 Retina contains visual receptors called
photoreceptors (rods and cones)
 3 layers
 Phototransduction is conversion of light
stimuli into neural signals
 Outer- Photoreceptors (rods & cones)
1. Photopigment absorbs light & breaks
down to 2 components
 Middle-Bipolar neurons
2. Hyperpolarizes rods/cones
 Inner-Ganglion cells (axons join & form
optic nerve)
3. Decrease in release of inhibitory
neurotransmitter
 Light passes through ganglion and bipolar
neurons before reaching photoreceptors
 Fibers partially cross over in optic chiasmRight half of brain interprets image from
left eye and vice versa
 Rods are abundant in the periphery of
the retina whereas cones are found more
frequently in the central areas
Optical illusions
 http://www.illusions.org/
 http://www.michaelbach.de/ot/
Sources
 Bogi, Stephen. "Human Eye Anatomy: Parts of the Eye." All About Vision. N.p., Feb. 2014.
Web. 12 Apr. 2016.
 "Anatomy of Your Eye ." Clarkson Eyecare . Clarkson Eyecare, 2014. Web. 12 Apr. 2016
 Dahl, Andrew. "Anatomy of Eye:Eyelids and Eyelaashes ." emedicinehealth . Ed. William C.
Shiel. N.p., 7 Apr. 2016. Web. 12 Apr. 2016.
 http://www.healthcommunities.com/refractive-errors-and-vision/refractive-errorscorrection-overview.shtml#sthash.nE5Xsrr7.dpuf
 Moresea’s Powerpoint