Proper lighting is essential in allowing people with low vision to function normally. However not all light bulbs are created alike. Each type of light bulb has advantages and disadvantages, especially when considered in relation to low vision. Picking the proper bulb is as important as picking the right brightness and location for a lamp.
The traditional light bulbs most people are familiar with are known as incandescent bulbs. Vision Aware, an online self-help source for the vision impaired, suggests they are not well-suited for room illumination since their concentrated illumination causes shadows. They are best used in task lighting, but they put out so much heat they are not practical for close-up lighting. Recent U.S. changes in light bulb production standards have made traditional incandescent bulbs an endangered species, but many homes have stocks of them stored away in closets and they are still a major factor in home lighting.
Tungsten halogen bulbs are technically also incandescent bulbs, but give off brighter and more concentrated light. They are also more energy efficient. Their biggest drawback is that they put out a large amount of heat for a given level of illumination, more than any other bulb listed here. This makes them poor choices for close-up lighting, and requires placing halogen lamps away from flammable materials such as curtains. Halogen bulbs also tend to burn out quickly, requiring frequent replacement.
Fluorescent lamps give off more diffuse light than incandescent or halogen bulbs, making them best suited for room illumination. They are cooler than the other bulbs so are well-suited for close-up lighting. The most notable drawback to fluorescent lighting is that it tends to flicker, which can be even more noticeable to people with low vision. Compact fluorescent lamps (CFLs) give steadier light, but some people with low vision still see a flickering, strobe-like light. Another problem with fluorescent bulbs is that they require special disposal due to the mercury they contain.
Many organisations, including Vision Aware, recommend full spectrum bulbs for people with low vision. These bulbs give off a cleaner light which closely resembles sunlight. However the charitable organisation Macular Degeneration Support cites research which shows high levels of blue light not only cause glare, but can damage the human retina over time. They admit the research is preliminary, but feel that until the effects of blue light spectra on the human eye are better understood, people with low vision should avoid full spectrum lights.