ENVIRONMENTAL MODIFICATION Flashcards
Kinds of environmental modifications:
Size
Distance
Color
Lighting
Glare
Contrast
Environmental modifications are best achieved by:
Site visits to the patient’s environment
Providing education to the patient on various ways in which he/she can optimize lighting and contrast
Environmental modifications ideally should be considered at two levels
- In the individual’s general environment
- In specific tasks performed within the environment
Examples of size modifications
Large print books
Large print cards
Larger clocks
Larger calculators
T/F
Physical enlargement of the object produces a small retinal image
F- enlargement
T/F
Decrease in distance of object can produce enlarged retinal image
T
The role of color is important in:
Warning of hazards
Indicating change in surface or level
Colour modifications
Bright colors
Solid bright colors
A walkway painted on the floor for incoming/outgoing traffic
Bright color cards attached to hangers
Bright light, appropriately applied
When considering lighting modifications in LV patients, we are concerned with two aspects:
Amount of light
The level of glare produced
Lighting requirement for a patient with cataract
High
Lighting requirement for a patient with DR
Moderate
Lighting requirement for a patient with Glaucoma
Moderate
Lighting requirement for a patient with Macular degeneration
Varies usually brighter
Lighting requirement for a patient with RP
Moderate to bright
Sensitivity to light for a patient with Cataract
High
Sensitivity to light for a patient with DR
Moderate
Sensitivity to light for a patient with Glaucoma
Moderate
Sensitivity to light for a patient with Macular degeneration
High
Sensitivity to light for a patient with RP
High
The modification of lighting can be determined by the
Inverse square law
Advantages of natural light
Most natural type of light
Appropriate for many tasks
Advantages of incandescent light
Readily available in a large variety of wattages
Light is concentrated
Better for “spot lighting” on near tasks
Light does not “flicker” like fluorescent light
Advantages of fluorescent light
Better for general room lighting
Illuminates a wider area than incandescent light
Does not create shadows
Cooler than incandescent
Advantages of combination incandescent and fluorescent light
Can be combined to create a comfortable environment
Approximates natural light
Some lamps come in socket for both types of bulbs
Advantages of halogen lights
Brighter than incandescent light
Gives more illumination and uses lower wattage
More energy-efficient than regular incandescent light bulbs
Advantages of LED lights
High efficiency
Do not produce external heat
Very long lifetime
Disadvantages of natural light
Inconsistent
Creates glare
Creates shadows
Changes throughout the day
Disadvantages of incandescent light
Not recommended for general room lighting
Can create shadows and glare
Becoming unavailable
High energy consumption
Disadvantages of fluorescent lighting
Light is not stable; can flicker
Can’t be dimmed as easily as incandescent light
Glare can be described in three ways
Disability
Discomfort
Environmental
Arises from problems with the ocular media like the cornea or lens
Disability glare
Refers to stray light that reduces visual comfort
Discomfort glare
Refers to glare which results in poor resolution of the retinal image
Environmental Glare
It may be caused by glossy pages or particles in the air or on the viewing surface
Environmental Glare
Signs and notices
Bathroom signs not sensitive to patients with LV
Bathroom signs that display better contrast
Well-contrasted signs
Interior design
Wide entrance door
Automatic sliding doors must have distinctive warning strips on door
Use color or images to distinguish between doors and sidelights
Staircase should bear high contrast nosing and handrails
Tactile map with Braille
A well-demarcated and contrasted door
Exterior design
Signposts, lighting columns, litter bins and seating should be out of the line of pedest travel
A well-contrasted walkway with light posts
Placement of vegetation as boundary indicators
High contrast guide paths are required
Placement of tactile tile as path indicators
Electronic card readers
Tactile map with audio device
Designs to increase mobility outdoor
− Infrared transmission system
− Satellite navigation system
− Global positioning system
− Universal mobile telecommunication system
− Vision substitution
Designs to increase mobility indoor
− Talking sign post
− Easy Walker
Designs to increase mobility in government policy
Tactile maps
Tactile guide paths
Tactile signs for toilets
