Lecture 1: 11/9

Question 1

list the 3 ocular axes

Answer 1

1. geometric (anatomical)
2. optic
3. visual

Question 2

geometric (anatomical) axis is

Answer 2

saggital section of the eye (right down the center)

Question 3

optic axis is based on

Answer 3

passage and refraction of light through the eye (cornea and lens)

Question 4

location of optic axis is

Answer 4

through the centers of the refractive elements of the eye (cornea and the lens)

Question 5

visual axis (physiological) is

Answer 5

from the object of regard to the fovea through the nodal point of the lens

Question 6

geometric axis is if you drew a line from

Answer 6

anterior pole to posterior pole

Question 7

anatomical axis length for an adult is

Answer 7

24mm

Question 8

most of the growth of the human eye takes place

Answer 8

in the first 3 years

Question 9

growth pattern lengths for the eye at birth, 3 years, and 13 years

Answer 9

birth: 16-17mm
3 years: 22.5-23mm
13 years: 24mm

Question 10

definition of the eye’s equator

Answer 10

a line equidistant from the anterior pole to posterior pole

Question 11

“horizontal” and “vertical” distances of the eye are different, what are the values?

Answer 11

vertically: 23mm
horizontally: 23.5mm

Question 12

disproportions of the eye are

Answer 12

not completely round: wider than it is tall

Question 13

definition of the meridian

Answer 13

a line 90 degrees from the equator

Question 14

volume of the eye

Answer 14

6.5cc

Question 15

weight of the eye

Answer 15

7.5 gm

Question 16

3 tunics/ layers of the eye are

Answer 16

1. fibrous
2. vascular
3. retinal (neural)

Question 17

layers of the eye from outermost to innermost

Answer 17

(outermost) fibrous -> vascular -> retinal (innermost)

Question 18

the fibrous tunic is composed of what two structures?

Answer 18

cornea and sclera

Question 19

part of the fibrous tunic that is anterior and 1/6 of tunic

Answer 19

cornea

Question 20

part of fibrous tunic that is posterior and 5/6 of tunic

Answer 20

sclera

Question 21

cornea and sclera are both composed of what types of connective fibers?

Answer 21

collagen fibers 
(same fibers extend from cornea into sclera)

Question 22

vascular tunic structures (from posterior to anterior)

Answer 22

choroid, ciliary body, iris

Question 23

choroid is located ____ and consists of ____ fraction of the tunic

Answer 23

posterior and 3/4 of the tunic

Question 24

purpose of the choroid is to

Answer 24

supply nutrients and oxygen to structures exterior (sclera) and interior (retina)

Question 25

ciliary body is the

Answer 25

muscular band that is involved in changing the lens focusing

Question 26

iris is the ___ most component of the vascular tunic

Answer 26

anterior

Question 27

is the iris a completely continuous part of the layer and why?

Answer 27

no, hole in the anterior part called the pupil

Question 28

the purpose of the iris is to

Answer 28

be the diaphragm that can enlarge or reduce the pupil

Question 29

embryology of the retina

Answer 29

during embryological development- retina is an out growth of the brain

Question 30

what does the retina do?

Answer 30

changes light energy to a neuro-chemical signal

Question 31

what is the most important property of the cornea

Answer 31

transparency

Question 32

list of 3 factors that influence transparency of the cornea

Answer 32

1. regularity in stroma
2. smoothness
3. avascularity

Question 33

in the cornea, all the collagen fibers are in a layer called the

Answer 33

stroma

thickest

Question 34

fiber vs. cell arrangement in stroma

Answer 34

collagen fibers regular and precise arrangement

very few cells, lots of collagen fibers

Question 35

list of 4 conditions for factors influencing transparency of cornea

Answer 35

1. normal metabolism
2. nutrition, oxygen
3. water, H2O
4. health of cornea

Question 36

cornea/lens refractive element percentages

Answer 36

cornea 65%

lens 35%