Helping people with Visual Impairment Flashcards
What to say when seeing a px
- What is causing the sight loss
- Which eye disease ?
- How long have they had it ?
- What difficulties do they have?
- What do they want help with?
- What help have they received to date?
- History taking - how long condition
- Any struggles/difficulties - how to help them
What else to ask px
What can px see - SVD/SVI/SVN - objective measurement of what they can see
- Measure each eye individually then both eyes together
-
What’s the problem with SVD chart
Its all 100% contrast - black on white
What chart is used to measure contrast sensitivity
Penny Robson chart
What is contrast sensitivity
How well they can see at different contrasts - top = dark, bottom = light i.e. letters are faded out
- Letter sizes are constant
Eyecare journey
Each person with a visual impairment goes on their own “Eyecare journey” Journey is never ending There are journeys within the journey “Eyecare” implies focusing on health Journey is often very difficult What can be done to make it easier?
What are the 3 B’s to help px’s
Bigger
Brighter
Bolder
How do the 3 B’s help
Bigger = read print more easily - bring closer Brighter = dark room - see things -Bolder = easier to read
How to make things bigger
Doubling the size of an object gives X2 magnification
Move closer
Half the distance will make things twice the size
Use magnifiers
Use large print
Try adapted equipment e.g. large faced clocks and watches
Try larger TV screens
Try large labels and notes
How to make things bolder
Use colour and tone contrast Try a bold font when using a PC Try white crockery on a dark tablecloth Try white cups for tea and coffee Try white edges on dark steps and dark edges on white steps
How to make things brighter
Use increased light
What is purpose of magnifiers
Make things bigger
Optical low vision aids
What are the types of magnifiers
-Spectacle Magnifiers
-Hand-held magnifiers
Illuminated
Non-Illuminated
Stand magnifiers
Illuminated
Non-Illuminated
Other Magnifiers
Bar Magnifier
Flat Field Magnifier
Telescopes
What’s the formula for magnification and example
Magnification= F/4
e.g. If F=12DS, Magnification=12/4=3x ( how much bigger it would make it )
Whats the magnification for 4DS
1X
What does magnification assume
Working distance of 25 cm
Spectacle Magnifiers: Advantages
Hands free
Cosmetically and psychologically acceptable
Different types possible-e.g. bifocals
Large Field of view
May flip up/out of line of sight - can wear them on nose and read
May be able to use both eyes
Spectacle Magnifiers: Disadvantages
Short working distance Conspicuous if clip on/head band mounted May be heavy - due to higher power of lens Lens errors May be difficult to use both eyes together
What happens when high power
More errors in lens due to optical properties
Cant use both eyes together
Hand-Held Magnifiers
Available up to about 6x non-illuminated and about 15x illuminated ( light )
Cosmetically/Socially acceptable
Cheap
Portable
Easy to use
Can be used at any distance from the eye - adjust working distance to suit your needs
Lower powers available in larger diameters
Hand-Held Magnifiers: Disadvantages
Not good if hand tremor present or arthritic especially at higher powers
Best suited for short duration tasks e.g. reading off medicine to see how many times to use
Can be used inappropriately
Internal illumination can make magnifier heavy
Stand- Magnifiers: Advantages
Up to 20x available Both hands are available to use and working distance easily maintained - dont have to adjust working distance Lower powers may allow use of pen Stable Hold them flat in page
Stand Magnifiers: Disadvantages
May block light although illuminated varieties available
Can be bulky and heavy especially lower powers - cant put in pocket
Might be difficult to read a book because of the hump caused by the binding
Difficult to perform tasks underneath at high powers - stand is v.small