4.2.2 LV

Question 1

what is a Galilean telescope

Answer 1

one convex( obj lens) and one concave eye piece lens
light parallel in and parallel out
image errect

Question 2

what is astronomical/keplerians

Answer 2

2 convex lens
light parallel in and parallel out
image inverted - correct with prism

Question 3

why use telescopes as LVA

Answer 3

used for distance tasks
provide magnification without having to get any closer to the object

Question 4

Why use near the tescopes

Answer 4

• provides longer wd
  supplementary lenses in galilean
• has extra plus Lens onto and add extra amount of plus to objective lens to compensate for close working distance
• increase lens separation in astronomical
• this reduces working distance
• variable focus

Question 5

pros of NV telescope

Answer 5

longer WD

Question 6

cons of nv telescope

Answer 6

cosmesi
weight ( esp astronomical)
smaller fov
limited depth of focus

Question 7

what are examples of distance telescopes

Answer 7

galilean 3-4x mag
clip on 3x mag
spectacle mounted 3 4x
keplarian 6x

Question 8

what are examples of near telescope

Answer 8

galilean 2.5x mag
keeler LVA 22- up to 8x

Question 9

how can you adapt a phone

Answer 9

bigger - larger text , zoom in , magnifier setting or app
contrast - bold text , invert colours , colours contrast
brightnesss- increase it , increase saturation
audio - tex to voice, audio desciption

Answer 10

Question 11

what are complex lv aids

Answer 11

• Spectacle mounted telescopes
• Field expanders
• CCTVs
  
  • X-Y table
  • Television readers
  • Head mounted
  • Portable
• Intraocular telescope (not really required but may impress assessor)

Question 12

CCTV ADVANTAGES

Answer 12

• CTV Advantages:
  
  • High Mag - up to 70X, zoom in & out
  • Contrast reversal & enhancement - enhances from 70 to 100%, reverse polarity, colour options & margins to use as typoscope
  • Better posture - not looking downward
  • Socially acceptable - at work & school
  • Binocular
  • Good depth of field

Question 13

CCTV DISADVANTAGES

Answer 13

• Expensive!
• Hard to use - need practice for all the controls!
• ## Not very portable although TV readers are

Question 14

WHAT Are non optical aids

Answer 14

• typoscope
  tactile( place on jars for px to differentiate which jar is for what)

bumpons
braille
talking devices ( audible liquid level indicator. talking tins/clocks)

Question 15

what are apps

Answer 15

be my eyes
identifi ( app that looks at any image and relays verbally what it is)
voice over
google maps
ebooks audio books

Question 16

where can you get lv

Answer 16

RNIB, Low vision clinic
Macular society
Eschenbach is a German company that specialises in LVAs that are premium quality. Very good to suggest to sight impaired patients

Answer 17

Desktop magnifiers, or CCTV’s (closed circuit televisions), are ideal for low vision users. They use a camera to project a magnified image onto a monitor. T