Low vision non optical devices

low vision, optical devices, non optical devices, field enhancement, NOIR filters, writing guides, Typoscopes, Notex, signature guides, bold line copy

1. Low vision Non optical
Devices
Raju Kaiti, M. Optom
Consultant Optometrist, NEH

2. Non-optical devices
Play an important role in the successful
use of many low vision optical devices.
Uses relative size, illumination, position,
contrast, color, or other sensory inputs
for their effects.

3. Non-optical devices
Improve functional vision
Cheaper than optical devices
Easily available for usage

4. Non-optical devices
Helpful in increasing
Illumination level
Contrast
Physical comfort
Makes things easier to see by modifying
their color, contrast, shape,size and
position

5. Non-optical devices
Non optical devices=Assistive Technology
Piece of equipment, product, system or software
used to
Increase, maintain or improve functional capabilities of
individuals with sight loss

6. Types of nonoptical devices
Relative size and larger assistive devices
Glare, contrast, and lighting control devices
Posture and comfort mentinance devices
Handwriting and written communication
devices
Medical management devices
Orientation and mobility management
techniques and devices
Sensory subsitution devices

7. Relative size and larger assistive
devices
Large print materials = best example
E.g. enlarged photocopy materials and
computer printouts of large font size
Can make large print easily using
photocopies
Keep in mind margins, spacing and type
style
Arial narrow
Double line spacing
18 font size

8. Relative size and larger assistive
devices
Poet Compact - Reader
Magic 8.0

9. CCTV
Playing Cards
Large Button Dial
Phone

10. Pros and Cons
Advantages:
Cosmesis-the individual is able to read looking like a
person with normal vision
Disadvantages:
Books are too heavy and bulky and therefore difficult to
hold for long hours
Less available

11. Glare, contrast and light control
Contrast is important in enhancing functional vision
Patients with low contrast VA will complain about reading bills and
medicine labels etc
Increasing illumination level will easily enhance contrast
Illumination
Wall attached lamp/ over head reading lamp
Incandescent light – 60 W (longer wavelength- more
Halogen light – high intensity
Fluorescent light – 11W , blue spectrum
Neodymium bulb – 30% less UV & 20-28% less infrared than
incandescent bulb
Shades
Tennis shades, caps, hats, side-shields, visors

12. Adequate light ( natural /
lamp) for daily tasks

13. Glare, contrast and light control
Different eye conditions require different lighting level
Patients with RP require higher illumunation-
recommend them to use flashlight
Glaucoma and cataract produce glare-patients
benefit from different tinted lenses to control glare,
or a peaked cap roduces greater visual comfort
Albinism requires controlled or indirect lightings-
proper seating arrangements against direct sun or
use of curtains will help in lighting control

14. Glare, contrast and light control
Filters
Reduce glare, enhance contrast & reduce
adaptation time
NOIR-
photophobia and glare
absorb UV (200-400nm) near infrared
( 800-1400nm)
Younger protective lens
Filter UV and short wavelength blue light

15. NOIR & CPF
lenses

16. Glare, contrast and light control
Corning photochromatic
To protect eyes with progressive retinal
degeneration
Retinitis Pigmentosa- CPF 550 nm filter-
reduce scotopic transmittance and allow
photopic transmittance
CPF 450 – glare of fluorescent light, CPF
550XD- aniridia, achromatopsia
Glare cutter ( 390-410nm)- cuts 100%UVB,
99% UVA

17. Filters
Normal View 50% Brown Tint
CPF 511 CPF 527

18. Glare, contrast and light control
Anti-reflective coatings
3.87 – 5.32% of light lost at each surface
Single layer – multiple layer
Higher the index – greater need of
antireflective coatings
Materials – metallic chlorides and fluorides,
metals such as lithium sodium and alkaline
earth metals like magnesium.

19. Glare, contrast and light control
Mirror coatings
Reduce transmittance by absorption & reflection
Typoscopes
Reduce unwanted glare from surface
Pinholes
Pinholes reduce blur circle- in media opacities,
corneal involvements, cataracts
Stenopaic slits
Placed horizontally
Control illumination

20. Multiple pinholes under high illumination
Typoscopes – a reading guide cut off glare

21. Color and contrast
Adjustment of appropriate color and contrast
around the working environment
Wall and ceiling color
Furniture and decorating materials
Color the wall root, railing and staircase
Door and windows knob and handle
Kitchen vase and vessels
Edges of the staircase
Bed sheet, curtain, pillow cover and table cover
Floor color – non-skid

22. Environmental modificationPainted edges of Staircase

23. Contrast in Kitchen

24. Talking Color Detector

25. Posture and comfort maintenance
Reading devices require closer reading
distances
Patients need to bend to maintain close
diatance
Causes discomfort and stress
Adjustable reading stand recommended

26. Posture and comfort maintenance
Reading racks, book stand, lap desks,
copy holders
Reading stand
Material tilt 45- 70 degrees of the vertical.
High powered stand magnifier- if appropriate
tilting, improve legibility and reduce fatigue
Telescopes
ring stand, head band

27. Reading Stand
Telescope attached with Headband

28. Hand writing and written communication
Signature guide
Check guides
Reading guide
Letter writers
Bold felt-tip pens and
3B pencils (Boldness
increases contrast and
makes reading easier)
Type of paper used
Bold line paper
Large print typewriters

29. Non optical devices
Reading lamp
Reading stand
Writing guide
Reading guide
Signature guide
Bold line note books and papers
Black ink bold tip pens
Soft lead pencil – 2B,4B,6B
Needle threader
Notex etc...
Black cards with rectangular cut outs horizontally along the card
The patient can feel the empty cut out spaces and write

30. Notex
It is a rectangular piece of cardboard with
steps on top right corner which helps in
identifying the currency of the note
1st cut indicates Rs. 500, 2nd cut indicates
Rs.100, 3rd cut indicates Rs 50 and so on.
It is a rectangular piece of cardboard with steps on top
right corner which helps in identifying the currency of the
note
1
st
cut indicates Rs. 500, 2
nd
cut indicates Rs.100, 3
rd
cut
indicates Rs 50 and so on.

31. Devices for reading
Reading materials with enlarged and high contrast print
Typoscopes (reading guides)
Fixed reading stand
Adjustable reading stand
Illuminated reading stand
An enlarged and high contrast calculator
A talking calculator
A talking dictionary
Talking books
Tape recorders
Reading materials in braille
Tactile cards

32. Medical management
Monitoring blood glucose
Large print syringe
Syringe with magnifiers ( optical device)
Preset dosage
Pre-filled syringes- filled with clicking sounds
Comparing the color chart for urine moist strip using
plane white background and good illumination
Monitoring blood pressure
Readout sphygmomanometers for hearing problems
Monitoring temperatures
Large readout thermometers and talking thermometer

33. O & M management
Orientation is using the remaining senses to establish
one’s location in one’s environment
Mobility is an art of moving from one place to another
independently, safely and gracefully
Mobility cane- cost effective and easily available
Foldings and unfolding models
Cane is a safe mobility device and universal techniques
used.

34. O & M management
Sighted guide
Canes
long cane, folding and collapsible canes
Dog guides
Electronic travel aids
Pathsounder
Sonic Pathfinder
Laser cane
Mowat sensor
Nightscope
Night vision devices

35. Sensory-substitution devices
Auditory substitution
Talking books
Tactile substitution
Basic touch
Braille – six dots
Moon- nine characters (roman letters)
Fishburne alphabet
Paperless braille

36. Basic cells of Braille

37. Sensory-substitution devices
Braille writer
Braille Embosser & Printer

38. Others for DLS
Concave mirror- shaving
Needle threader
Iron in a wooden box
Easy say stop – level of liquid
Flash torch light
Buttons of different colors
Ropes for plating and unplating hair
Notex – notes identifier
Different size of currencies- by tactile / grouping
Umbrella

39. Devices for recreation
Enlarged Ludo
An enlarged chess set
An enlarged high contrast set of playing cards
Enlarged and colorful footballs
An enlarged and high contrast carrom board
with large and bright colored goals
A TV with and enlarged screen and bright
colors

40. Trainings
Eccentric viewing training
The voluntary use of an extra foveal locus or
loci for fixation with the goal of improving the
visibility of the target viewed.
Some learn on their own while others do not,
need to be trained.
Scanning and tracking training

41. Relative size and larger assistive devices
Large print
Books, magazines, newspaper, dictionaries,
thesauri, atlas, cookbooks, encyclopedias, bibles
Photocopy machines ( e.g. A4 size to A3 size)
Computer with large prints font
Computer software program
Large print typewriters
Others
Telephone dial, bank checks, watches, clocks,
calculators etc
Games like cross word puzzles, playing cards, chess
checkers, bingo etc.
5/20/2014APPROACH & ASSESMENT OF LVC-CME 80
“Visually disabled are not fallen souls”
“Positive attitude towards them will make them
socially amicable, psychologically adjustable and
educationally sound”
The unlimited opportunities and experiences
extended to them will make them physically fit
mentally alert and totally independent in the
community