PREFINAL

Question 1

Consist of one or more lenses placed between the eye

Answer 1

Optical Devices

Question 2

Optical devices is also known as

Answer 2

Low vision devices

Question 3

2 types of optical devices

Answer 3

Distance
Near

Question 4

A type of distance optical devices

Answer 4

Telescope devices

Question 5

Types of near optical devices

Answer 5

Hand held magnifier
Stand magnifier
Spectacle magnifier

Question 6

What optical device produces an enlarged virtual image behind the magnifier

Answer 6

Hand held magnifier

Question 7

In hand held magnifier, distance correction should be used because the image is formed at ___

Answer 7

Optical infinity

Question 8

Used for near viewing especially reading or any near activity

Answer 8

Hand held magnifier

Question 9

Advantages of hand held magnifier

Answer 9

Variable eye to lens distance
Normal reading distance
Convenient for short term tasks
Fairly inexpensive
Portable

Question 10

Disadvantages of hand held magnifier

Answer 10

Tremors in older patients can cause problem in maintaining focus
Steady handling is required
Decreased field of view
One hand is occupied

Question 11

What optical device produces an enlarged virtual image in front of the eye

Answer 11

Stand magnifier

Question 12

An optical low vision device used for near

Answer 12

Stand magnifier

Question 13

Optical device helpful for school aged children and can be used in high magnification

Answer 13

Stand magnifier

Question 14

Advantages of stand magnifier

Answer 14

Device of choice for tremors, arthritis, constricted fields
May have its own light source
Portable

Question 15

Disadvantage of stand magnifier

Answer 15

Image distortion
Reduced field of view
Needs constant head down for reading
Lens mounting
Poor posture is maintained
Requires a flat surface to place reading material

Question 16

2 telescopic devices

Answer 16

Galilean telescope
Keplerian telescope

Question 17

Elements of telescopes

Answer 17

Objective lens
Eyepiece lens

Question 18

Telescope which comprises of convergent objective lens and divergent eyepiece lens

Answer 18

Galilean telescope

Question 19

Most commonly used telescope in low vision assessment

Answer 19

Galilean telescope

Question 20

Image formed by Galilean telescope

Answer 20

Upright image

Question 21

It comprises of a negative eye piece lens and a positive objective lens

Answer 21

Galilean telescope

Question 22

Advantages of Galilean telescope

Answer 22

Small compact light unit
Easy to produce
Upright image

Question 23

Disadvantage of Galilean telescope

Answer 23

Low magnification 2x-3x
Restricted field of view

Question 24

It comprises a convergent objective and eyepiece lens

Answer 24

Keplerian (Astronomical) Telescope

Question 25

Image formed by Kpelerian telescope

Answer 25

Inverted image

Question 26

Advantages of Keplerian telescope

Answer 26

Larger field of vision High magnification 6x-8x

Question 27

Disadvantage of Keplerian telescope

Answer 27

Inverted image Heavy Complicated Difficult to use

Question 28

Criteria used when looking at a low vision telescope

Answer 28

Maginication extent Ability to telescope to transmit light Field of view

Question 29

The greater the amount of magnification, the smaller will be the ________

Answer 29

Field of view

Question 30

Electronic LVD used forr near work

Answer 30

CCTV system

Question 31

Disadvantages of CCTV:

Answer 31

Typically not portable Expensive Takes time to learn and handle, but very useful if adapted properly.

Question 32

A magnifying aid held in the hand in front of the eye for viewing small objects at close range. It is good for spot viewing or reading, with usual powers of 2x to 5x

Answer 32

HAND HELD MAGNIFIER

Question 33

A magnifying aid with internal illumination held in the hand in front of the eye for viewing small objects at close range. It is good for spot viewing or reading, with usual powers of 2x to 5x

Answer 33

ILLUMINATED HAND HELD MAGNIFIER

Question 34

A magnifying aid which is compact and can be folded, and is held in the hand in front of the eye for viewing small objects at close range. It is good for spot viewing or reading, with usual powers of 2x to 5x

Answer 34

FOLDABLE MAGNIFIER

Question 35

A magnifying aid fitted in a casing and held on the object to be viewed at close range. It is good for extended reading and is usually used in conjunction with a reading stand. Its usual powers range from 2x to 15x

Answer 35

STAND MAGNIFIER

Question 36

A magnifying aid fitted in a casing with internal illumination and held on the object to be viewed at close range. It is good for extended reading and is usually used in conjunction with a reading stand. Its usual powers range from 2x to 15x

Answer 36

ILLUMINATED STAND MAGNIFIER

Question 37

Type of stand magnifier that is a transparent magnifying aid held on the reading material. It provides good contrast and is usually available in 1.5x to 2.5x

Answer 37

DOME OR BAR MAGNIFIER

Question 38

A combination of lenses fitted in a tubular form to view objects from far distances to get a magnified view. Their powers range from 2x to 10x

Answer 38

TELESCOPES

Question 39

Telescope which can be used to view objects at close ranges i.e. 25cm to infinity

Answer 39

EXTRA-SHORT FOCUS

Question 40

Telescope to view near objects with a clip to attach on the spectacle frame. It is good for intermediate tasks, with powers from 2x to 4x

Answer 40

NEAR CLIP-ON MONOCULAR