Optical Appliances Flashcards
0
Q
Disadvantages hand mags
A
Not good for shaky hands
Use up a hand
Restricted field of view
Higher powers difficult to focus
1
Q
Advantages hand mag
A
Inexpensive Easy to use Socially acceptable Lightweight Portable Binocular viewing at lower powers
2
Q
Advantages stand mags
A
Fixed focal length Easy to use Illuminated available Inexpensive Hands free
3
Q
Disadvantages stand mag
A
Bulky
Require a flat surface
Needs reading specs or accommodation
Limited field of view with high mag
4
Q
Advantages of high reading adds
A
Wide range of mag
Reasonable field of view
Relatively inexpensive
Hands free
5
Q
Disadvantages high reading adds
A
Reduced working distance Binocular/convergence problems Illumination Aberrations Heavy
6
Q
Advantages telescopes
A
Only LV for DV
Wide range of mag
Monocular or binocular
7
Q
Disadvantages telescopes
A
Expensive
Can be difficult to use
Reduced field of view
8
Q
Advantages CCTV
A
Wide mag Wide fov Variable mag Can be used for writing Binocular Increase or reverse contrast
9
Q
Disadvantages CCTV
A
Expensive
Not available on NHS except in Wales
Usually non portable
Bulky
