PHYSIOLOGY OF VISION

Question 1

Light is a form of electromagnetic
radiation composed of particle called…….

Answer 1

Photons
that travel in wavelike fashion.

Question 2

Protection is provided by :

1……….
2……….

Answer 2

1-Eyelashes
2- Secretion of tears from the Lacrimal glands

Question 3

Functions of sclera :
1……
2……

Answer 3

A. Provide the attachment for the ocular muscles
B. Provide mechanical support

Question 4

The functions of cornea :

Answer 4

A- Allows the light to pass to the inside of the eye (that is why it is transparent).
B- It refracts \ bends \ twist \ change the angle of the light rays.

Question 5

Uvea is …..

Answer 5

Choroid

Question 6

Ciliary Muscles : provide the attachment to the lens through ………

Answer 6

suspensory ligaments or
zonules

Question 7

This choroid layer get modified anteriorly and give rise to……..

Answer 7

ciliary body

Question 8

The pathway of light into the eye:

Answer 8

1- The light passes into the cornea

2- Anterior chamber: a space between the cornea and the iris
3- Pupil
4 Posterior chamber: a thin space between the iris and the lens
5- lens
6- Vitreous chamber or cavity
7- focal point in the retina

Question 9

…………………… is a transparent fluid which provide nutrition to the
avascular cornea”

Answer 9

Aquas humor

Question 10

Ability of the eye to change the focal length of the
lens by changing the curvature of the eye lens

Answer 10

Accomodation

Question 11

In the Accommodation the Ability of the eye to change the focal length of the
lens by changing the curvature or concavity of the eye lens

Answer 11

curvature

Question 12

Accommodation is the Ability of the eye to change the ………..

Answer 12

focal length of the lens

Question 13

Which structures response to change the shape
of the lens during accommodation ?

Answer 13

the ciliary muscle and suspensory ligaments

Question 14

The lens assumes a more spherical shape
This occurs during accommodation on a…………object being viewed

Answer 14

Closer

Question 15

Focusing on near objects
needs less/more bending of the
light rays

Answer 15

More

Question 16

Lens flatter during accommodation on a……. distant object being viewed

Answer 16

more

Question 17

The Accommodation occurs in both …….. and …..

Answer 17

Lens and Irus

Question 18

Parasympathetic causes pupillary ……….. by contracting the ..…….muscle of the eye

Answer 18

constriction

circular

Question 19

Sympathetic causes pupillary ……… by contracting the ……muscle of the eye.

Answer 19

dilatation

radial

Question 20

Refraction (conversion) means :

Answer 20

changing the angle of the light.

Question 21

The……. and…….. are refractive structures of the eye They offer…….. surfaces to focus diverging light rays

Answer 21

cornea

lens

convex

Question 22

What is the constant refractive structures ?

Answer 22

cornea

Question 23

What is the modifiable refractive structures ?

Answer 23

the shape of the lens

Question 24

Convex structures of the eye produce…….. of these diverging rays

Answer 24

convergence

Question 25

The refractive power of a lens is measured in……..

Answer 25

diopters

Question 26

The human eye has
………..refractive power of diopters at rest

Answer 26

60

Question 27

The nearest point to the eye at which an object can be brought into clear focus by accommodation is called the
…………..

Answer 27

near point of vision

Question 28

The near response is compost of 3 parts

Answer 28

accommodation, the visual axes converge and the pupils

Question 29

The near point recedes throughout life with
advancing age results in loss of accommodation
Condition is known as…….

Answer 29

Presbyopia

Question 30

Emmetropia

Answer 30

Normal eye