VISION SCIENCEJOSEPH 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

Posteriorsegment

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

aqueous

Optic nerve

retina

Color part: iris

Black part: pupil

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 SEGMENTLens: it’s crystalline

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

^ Look it’s crystal-y >

POSTERIOR SEGMENTVitreous: “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

Bordered by the BACK of the

cornea, and the FRONT of the iris

Posterior chamber

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 cornea, sclera

tunica vasculosa aka “uvea” iris, ciliary body, choroid

tunica nervosa retina

sclera : the white part, fibrous

Fiber x a gazillion = tissue

Key functions: SupportStrengthProtectsStructured

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 fibrosa = sclera + cornea

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 changesthe 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: overviewis the back of the eyehas certain landmarksIs 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 featuresConcentric subdivsions

Retinal landmarks: the macula

Key featuresContains 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 featuresAvascular :Contains no blood vessels

Retinal landmarks: the Fovea

Key featuresConcentrated with photoreceptors.......................is the area of sharpest visionTechnically, one of the subdivisions of the maculaThe retinal layers get pushed aside at the foveal pit

Retinal layers

Key featuresEach layer has different cell types

Retinal layers: Photoreceptors

Key featuresMade 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 featuresConnect photoreceptors to ganglion cellsCross-talk to each other via horizontal cells

Retinal layers: ganglion cells

Key featuresReceives information from bipolar cellsCross-talk with other bipolar cells via amacrine cellsAxons group together to 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: ganglion cells form the optic nerve

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!

Eyeball

Tunics

Fibrosa

Cornea slcera

Vasculosa

Uvea

Iris Ciliary body choroid

Nervosa

retina

anterior segment

Anterior chamber

Bordered by the BACK of the

cornea, and the FRONT of the

iris

Posterior chamber

Bordered by the iris and the ciliary body

posterior segment

Back of the lens through the

vitreous

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….