Transcript Eye Anatomy - Dsapresents.org

LECTURE 1: EYE ANATOMY
Liana Al-Labadi, O.D.
EYE ANATOMY
http://everlastingelephants.blogspot.com/2009/08/what-is-eye-cataract.html
EYE ANATOMY

The orbital bone
The eye socket
 Formed by:

Cheekbone
 Forehead
 Temple
 Side of nose



http://commons.wikimedia.org/wiki/File:Eye_orbit_anatomy_anterior2.jpg
Eye is cushioned within orbit
by pads of fat
Lacrimal gland


Produces tears
Tears drain through the
nasolacrimal duct
http://mwsu-bio101.ning.com/forum/topics/distinct-human-celltypes-1?commentId=2263214%3AComment%3A10331
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 eye
 Covers the sclera and the
inside of the eyelids
 Function:


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 eye”
 Tough, opaque tissue that
extends around the eye
 Surrounds the eye and gives
the eye its shape
 The sclera is attached to the
extraocular muscles

http://www.thirdeyehealth.com/sclera.html
EYE ANATOMY

Extraocular Muscles
6 extraocular muscles that are
attached to each eye
 Help move the eye left, right,
up, down and diagonally
 These 6 muscles are:

Superior rectus
 Inferior rectus
 Medial rectus
 Lateral rectus
 Inferior oblique
 Superior 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 eye
Avascular

Only organ that has no blood
vessels
http://commons.wikimedia.org/wiki/File:Cornea.jpg
EYE ANATOMY

Anterior Chamber (AC):



Fluid-filled space
Behind the cornea & in
front of the iris
Fluid = Aqueous humor
(AH)

AH helps nourish the cornea
& the lens
http://www.djo.harvard.edu/files/2528_310.jpg
http://www.goodhope.org.uk/departments/eyedept/angleclosureetc.htm
EYE ANATOMY

Pupil (P):


Central opening of iris
Iris (I):
Ring shaped tissue
 Colored part of eye
 Controls the amount of light
that enters the eye


Two muscle fibers:

Contraction


http://www.bioconsulting.com/Bio_Tech_Assessment.html
Constricts pupil in bright light
Dilation

Dilates pupil in dark
http://www.goodhope.org.uk/departments/eyedept/angleclosureetc.htm
EYE ANATOMY

Anterior Chamber Angle
Located where the cornea meets
the iris
 Trabecular Meshwork

Site where aqueous humor drains
out of eye
 If AH cannot properly drain out
 Pressure build up inside eye


Causes optic nerve damage &
evetually vision loss = glaucoma
http://seniorhealth.about.com/library/conditions/blglaucoma2.htm
EYE ANATOMY

Posterior Chamber (PC):

Fluid-filled space


Aqueous 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
body
The 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-givepatients-high-definition-vision-better-than-2020/2558/
EYE ANATOMY

Vitreous Chamber:
Located behind the lens &
in front of the retina
 Filled with a gel-like fluid
called the vitreous humor
 The 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 image
 Consists of a specialized layer of
cells
 Converts light signals into nerve
signal then send these signals to the
optic nerve

hhttp://www1.appstate.edu/~kms/classes/psy3203/EyePhysio/human_retina.htm
Optic nerve carries the signals to the
brain
 The brain helps process the image

Rods- low light situations
 Cones- allows you to see color

http://www.answersingenesis.org/tj/v13/i1/retina.asp
EYE ANATOMY

Macula
Located in the central part of
the retina
 Responsible for giving sharp
central vision
 Used for reading, recognizing
faces, and watching TV
 Any 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_dege
neration_frequently_asked_questions
EYE ANATOMY

Choroid

A layer of tissue that is:
Located under the retina
 Separates retina & sclera



Mostly made up of blood vessels
Helps nourish the retina by
carrying the blood supply to the
eye’s internal structures
http://www.cnib.ca/en/your-eyes/eye-conditions/amd/the-eye/basics/Default.aspx
EYE ANATOMY

Optic Nerve
A bundle of 1 million nerve
fibers
 Responsible for transmitting
nerve signals from the eye to
the brain
 The optic disc is the front
surface of the optic nerve


http://cssd.us/body.cfm?id=802
The optic disc is visible on the
retina
http://www.wollongong.youronlinecommunity.com.au/wollongong-online/2008/50/walkthrulife/eyehealth.html