LECTURE 1: EYE ANATOMY

Liana Al-Labadi, O.D.Presenter: Gopal Singh Assist. ProfessorSGRD CON, Amritsar

EYE ANATOMYhttp://everlastingelephants.blogspot.com/2009/08/what-is-eye-cataract.html

EYE ANATOMYhttp://commons.wikimedia.org/wiki/File:Eye_orbit_anatomy_anterior2.jpg

The orbital boneThe eye socketFormed by:Cheekbone Forehead Temple Side of noseEye is cushioned within orbit by pads of fatLacrimal glandProduces tearsTears drain through the nasolacrimal duct

http://mwsu-bio101.ning.com/forum/topics/distinct-human-celltypes-1?commentId=2263214%3AComment%3A10331

EYE ANATOMYBones of the OrbitRoof: Front-less frontal, lesser wing of sphenoid boneLateral Wall: Great-Z greater wing of sphenoid, zygomatic boneMedial Wall: Smel(l)sphenoid, maxillary, ethmoid, lacrimal bonesFloor: Zip My Pantszygomatic, maxillary, palatine bones

EYE ANATOMY

Eyelids (L):Protection:Protects eye from foreign matter (dust, dirt, debris)Protects against bright light that might damage the eye Help spread tears over surface of eye- moist & comfort Eyelashes (L): Filter out foreign matter prevent it from getting into eye

http://www.medical-look.com/human_anatomy/organs/Eyelids_and_eyelashes.html

EYE ANATOMY

Conjunctiva (Conj):Thin, clear layer of skin Covering of the front of eyeCovers the sclera and the inside of the eyelidsFunction:Keeps bacteria and foreign material from getting behind eye

http://www.images.missionforvisionusa.org/anatomy/2005/11/conjunctiva-answers.html

EYE ANATOMY

Sclera (S):White of the eyeTough, opaque tissue that extends around the eye Surrounds the eye and gives the eye its shapeThe sclera is attached to the extraocular muscles

http://www.thirdeyehealth.com/sclera.html

EYE ANATOMY

Extraocular Muscles6 extraocular muscles that are attached to each eye Help move the eye left, right, up, down and diagonallyThese 6 muscles are:Superior rectusInferior rectusMedial rectusLateral rectusInferior obliqueSuperior oblique

http://media.photobucket.com/image/introduction%20to%20eye%20anatomy/trimurtulu/Eye.jpg

EYE ANATOMY

Cornea (K):Clear layer at the front & center of eye Located in front of the iris (colored part of eye)Function:Focus light as it enters eyeAvascularOnly organ that has no blood vessels

http://commons.wikimedia.org/wiki/File:Cornea.jpg

EYE ANATOMY

Anterior Chamber (AC):Fluid-filled spaceBehind the cornea & in front of the irisFluid = Aqueous humor (AH)AH helps nourish the cornea & the lens

http://www.djo.harvard.edu/files/2528_310.jpghttp://www.goodhope.org.uk/departments/eyedept/angleclosureetc.htm

EYE ANATOMYPupil (P):Central opening of irisIris (I):Ring shaped tissueColored part of eyeControls the amount of light that enters the eyeTwo muscle fibers:ContractionConstricts pupil in bright lightDilationDilates pupil in dark

http://www.bioconsulting.com/Bio_Tech_Assessment.htmlhttp://www.goodhope.org.uk/departments/eyedept/angleclosureetc.htm

EYE ANATOMYAnterior Chamber AngleLocated where the cornea meets the iris Trabecular MeshworkSite where aqueous humor drains out of eyeIf AH cannot properly drain out Pressure build up inside eyeCauses optic nerve damage & evetually vision loss = glaucoma

http://seniorhealth.about.com/library/conditions/blglaucoma2.htm

EYE ANATOMY

Posterior Chamber (PC):Fluid-filled spaceAqueous Humor!Immediately behind the iris but infront of the lens

http://seniorhealth.about.com/library/conditions/blglaucoma2.htm

EYE ANATOMY

Crystalline Lens:Clear, flexible structure Behind the iris & pupil Surrounded by a ring of muscular tissue ciliary bodyThe lens & ciliary body help control fine focusing of light as it passes through the eye

http://www.smartplanet.com/business/blog/smart-takes/artificial-lens-implant-to-give-patients-high-definition-vision-better-than-2020/2558/

EYE ANATOMY

Vitreous Chamber:Located behind the lens & in front of the retinaFilled with a gel-like fluid called the vitreous humorThe vitreous help maintain the shape of the eye

http://www.ophthobook.com/questions/question-how-many-chambers-are-there-in-the-eye

EYE ANATOMY

Retina:Acts like the film in a camera to create an imageConsists of a specialized layer of cells Converts light signals into nerve signal then send these signals to the optic nerveOptic nerve carries the signals to the brainThe brain helps process the imageRods- low light situationsCones- allows you to see color

hhttp://www1.appstate.edu/~kms/classes/psy3203/EyePhysio/human_retina.htmhttp://www.answersingenesis.org/tj/v13/i1/retina.asp

EYE ANATOMY

MaculaLocated in the central part of the retina Responsible for giving sharp central visionUsed for reading, recognizing faces, and watching TVAny disease that affects the macula will cause a change & impairment in the central vision

http://www.dukehealth.org/eye_center/specialties/macular_degeneration/care_guides/macular_degeneration_frequently_asked_questions

EYE ANATOMY

ChoroidA layer of tissue that is:Located under the retinaSeparates retina & scleraMostly made up of blood vessels Helps nourish the retina by carrying the blood supply to the eyes internal structureshttp://www.cnib.ca/en/your-eyes/eye-conditions/amd/the-eye/basics/Default.aspx

EYE ANATOMY

Optic NerveA bundle of 1 million nerve fibersResponsible for transmitting nerve signals from the eye to the brainThe optic disc is the front surface of the optic nerve The optic disc is visible on the retinahttp://cssd.us/body.cfm?id=802http://www.wollongong.youronlinecommunity.com.au/wollongong-online/2008/50/walkthrulife/eye-health.html

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