VISION
SCIENCE
JOSEPH NAYFACH, CLASS OF 2018
STEPHANIE MARTEN-ELLIS, CLASS OF 2017
CLASS STRUCTURE
Lecture everyday
End of class reserved for Study Questions/Q&A
Midterm on June 6th!
Final is cumulative: we’ll vote on the date
Quizzes = 20%
Midterm = 40%
Final = 40%
LET IT BE KNOWN…
We want you to learn! We want you to see what it’s really like to take
this class.
Always feel free to stick around, ask questions, email/text us anytime:
stephmarten@gmail.com 254-368-0653
jnayfach@gmail.com
415-847-8346
The quizzes are probably somewhat of a pain, but helps us know how
good a job WE’RE doing before we get the point of exams.
Curve?....(never say never, but) NO.
Hint: that’s what the quizzes are for 
LET IT BE KNOWN…
-This course is adapted from the course materials of Vision
Science I of the first year of the UCHO program
-this is the real stuff we get as students! How exciting.
-credit to Dr. Stevenson, who teaches the course in the fall.
EYEBALL BASICS
Anterior
segment
Posterior
segment
EYEBALL BASICS
See if you can match column A to column B:
1. Iris
A. the “gel” of the eye
2. Pupil
B. sends signals of incoming light to the brain
3. Cornea
C. the colored part of the eye
4. Lens
D. a watery fluid in the eye
5. Retina
E. the black part of the eye, lets light in
6. Optic nerve
F. the transparent, front surface of the eye
7. Aqueous humor
G. a crystalline solid that focuses light
8. Vitreous humor
H. the layer at the back of the eye that detects light
retina
Color part: iris
Black part: pupil
aqueous
Optic nerve
Pokey-outy part:
On this patient, who
has keratoconous, the
cornea is irregularly
shaped and easily
visible
ANTERIOR SEGMENT:
Anterior CHAMBER + posterior CHAMBER
= anterior SEGMENT
that pink thing: the Ciliary Body
- produces the aqueous humor
That other pink thing: the iris
-a good landmark
-divides the ant and post
chambers
Aqueous flows through the anterior segment
ANTERIOR SEGMENT
Lens: it’s crystalline
^ Look it’s crystal-y >
Key functions:
why that’s important:
It’s clear……………………….not clear = cataract
It changes shape…………….how we focus! By age 50, we can’t
do this anymore and we need reading
glasses or bifocals. This is called presbyopia.
=1/3 of focusing power………just keep in mind that the cornea is the other 2/3
POSTERIOR SEGMENT
Vitreous: “eye gel”
Key features:
Structured matrix of collagen
and hyaluronic acid……………………supports eye shape. Loss of
structure over time, liquefaction,
produces floaters
does not circulate like aqueous……...excess movement can pull on the
retina (traction) or totally detach
from the retina
eyeball
anterior segment
Anterior chamber
Posterior
chamber
Bordered by the
BACK of the
cornea, and the
FRONT of the iris
Bordered by the
iris and the ciliary
body
posterior
segment
Back of the lens
through the
vitreous
LAYERS/TUNICS
Another way to divide the eye…
Uses fancy anatomical vocabulary. It’s Latin, get used to it… 
tunica fibrosa
tunica vasculosa
tunica nervosa
cornea, sclera
aka “uvea”
iris, ciliary body, choroid
retina
tunica fibrosa = sclera + cornea
sclera : the white part, fibrous
Fiber x a gazillion = tissue
Key functions:
Support
Strength
Protects
Structured
tunica fibrosa = sclera + cornea
Cornea: it’s the clear part of this picture
Key functions:
Why it’s important/ aka “impress your path teacher”:
It’s clear ……………………corneal scars can lead to vision loss!
It’s avascular ………………this is why infectious are so dangerous!
it’s sensitive………………..loss of sensitivity can be a sign of some diseases
(*cough* herpes *cough*), or over-use of contact
lenses.
Focuses light………………provides 2/3 of the focusing power of your eye. Different
shaped corneas, or corneas of different thicknesses,
can change your glasses Rx
tunica vasculosa = Uvea = Iris + Ciliary Body + Choroid
Iris: the colored part
key functions:
-opens and closes the pupil
-this in turn, effects the optical quality of the image that the eye gets
Pupil borders the
pupillary zone
Iris “inserts” into the
ciliary body @ the
ciliary zone
The “angle” : where the iris meets the ciliary body.
Canal of Shlemm: a tube @ the angle
Key function:
why’s this important?:
Drains aqueous humor……………HINT: if it’s aqueous, it’s important in glaucoma
tunica vasculosa = Uvea = Iris + Ciliary Body + Choroid
ciliary body:
Key functions:
Why it’s important:
produces the aqueous humor…………………………aqueous function = glaucoma!
contains a muscle that changes
the shape of the lens…………………………………...accommodation, how we focus
tunica vasculosa = Uvea = Iris + Ciliary Body + Choroid
Choroid: layer of blood vessels
the lies between the sclera and
the retina
Key function:
Impress your path teacher:
provides BLOOD
+ NUTRIENTS
+ OXYGEN to the retina……...choroidal neovascularization refers to
the overgrowth of blood vessels in the
choroid. This is a major mechanism of
vision loss in macular degeneration
retina = tunica nervosa
Key features: overview
is the back of the eye
has certain landmarks
Is thin, yet made of layers
retina = the back of the eye
Key feature:
impress your path teacher:
spans the entire back of the eye
up to the ciliary body…………………………fundus is the clinical term for the
“back of the eye”
Retinal landmarks: the macula
Key features
Concentric subdivsions
Retinal landmarks: the macula
Key features
Contains pigment………………………..pigments are the chemicals that react to
light, and start the conversion of photons to
light signals. Looks yellow!
Retinal landmarks: the Fovea
Key features
Avascular :Contains no blood vessels
Retinal landmarks: the Fovea
Key features
Concentrated with photoreceptors.......................is the area of sharpest vision
Technically, one of the subdivisions of the macula
The retinal layers get pushed aside at the foveal pit
Retinal layers
Key features
Each layer has different cell types
Retinal layers: Photoreceptors
Key features
Made of rod cells……………………........................sees dim light for “night vision”,
none are located in the fovea
+ cone cells…………………………………….densely packed in the fovea,
responsible for color vision
Retinal layers: Bipolar cells
Key features
Connect photoreceptors to ganglion cells
Cross-talk to each other via horizontal cells
Retinal layers: ganglion cells
Key features
Receives information from bipolar cells
Cross-talk with other bipolar cells via amacrine cells
Axons group together to form the optic nerve
Retinal layers: ganglion cells form the optic nerve
Optic nerve: the connection from the retina to the brain
Key features
why we care
Basically where the “nerve cord”
of the eye starts………………………….is your blind spot.
can get damaged in MANY
diseases, so looking at the optic
nerve head will become a key
part of any eye exam.
Retinal layers: a second look
DON’T: learn the names of the layers for this class…that’s ocular anatomy 
DO: learn the names and functions of the cell types from the previous slide, in
their correct sequence!
DO: learn the names and functions of the cell types from the previous slide, in
their correct sequence!
DO: become familiar with anatomical organization, and each structure mentioned.
today we talked about two organizations
but all the organs and structures overlap. Just notice the terminology, b/c
those terms will show up again and again and again….
Eyeball
Tunics
Fibrosa
Cornea
anterior segment
Vasculosa
Nervosa
Anterior chamber
Posterior
chamber
Bordered by the
BACK of the
cornea, and the
FRONT of the iris
Bordered by the
iris and the ciliary
body
slcera
Uvea
retina
Iris
Ciliary body
choroid
posterior
segment
Back of the lens
through the
vitreous