Mobile 07748 020315 Optician@eyesathome.co.uk
Many visually impaired individuals are aware of their need for good
lighting but often try to improve matters by exchanging their current
60 watt incandescent bulbs in ceiling fittings for 100 watt varieties,
only to find that this does not noticeably improve their vision, only
the amount on their electricity bill!
It is important to have good general illumination throughout the home
or workplace, usually provided by central ceiling fittings, or fluorescent
strips (adequately diffused to prevent glare). Good general illumination
is especially important to many individuals, who find that they experience
reduced light / dark adaptation which in poorly lit areas can result
in potentially dangerous situations.
For close work, many visually impaired individuals find that they are helped by the provision of extra, positional task lighting. The type most frequently recommended is an 11 watt, white fluorescent tube, this is generally preferred, as it offers relatively wide coverage and is cool in operation, this is an important factor as many find it essential to position the head of the light very close to the viewed object in order to maximise the amount of reflected light and the amount of heat produced can cause problems.
When discussing the positioning of task lighting, it should be appreciated, that the amount of light reflected from a viewed object, doubles every time the distance of the light, is halved, therefore, the closer the light source to the viewed object, the more light will be reflected. We refer to reflected light, rather than the amount of light produced by a light source, as this is indicative of the amount of light available to assist vision.
As a general guide, the head of a task light, should be positioned
directly above the viewed object at a distance of about 20 cms and tilted
slightly away from the user.
If this distance is found to be restrictive then it is possible to position
it slightly higher, but care should be taken to ensure that it is never
higher than the user's line of sight as this will result in uncomfortable
glare problems.
Task lighting has many applications in everyday life and is often used
to great
benefit in the kitchen, dining room and office, as well as the sitting
or bedroom.
Correctly positioned task lighting can enable individuals to prepare
food, set dials, pour drinks and of course, see what they are eating!
Although we generally recommend fluorescent task lighting, some individuals,
find that daylight blue bulbs or halogen lighting are suited to their
needs. Care should however, always be taken to ensure that associated
glare and heat production are avoided.
It should also be mentioned, that although many Visually Impaired individuals find extra lighting to be beneficial, there are some uncommon eye conditions which require less light.