Reducing The Glare Of Your Lamps


Glare Problems With Lamps

Your new glass lamp shades has a problem. It's not a floor model so you have to put it on a table - otherwise it's too short. When you put it on a table, the shades are not low enough to cover the bulb. On top of that, the glass doesn't do a good job of cutting down the glare.

As a result, the light from the bottom of the lamp is very bright and gives off a strong glare which hampers your activities rather than helping. This happens with shades that are too short or too wide. Worse still, your lamp has bulbs that project downward! We offer some very specific steps in solving this problem.

1. Reduce The Wattage

Consider reducing the wattage of the light bulb from the recommended wattage. Most lamps use 60W or less, but you can go for bulbs that are 40W or 25W. The "color" of the bulb matters too. Go for a "soft white" rather than a "clear white" - the softness indicates that the glass is coated with a material which diffuses the light and reduces the glare.

2. Use A Compact Fluorescent Light

Switch to a compact fluorescent light bulb (CFL) that not only saves energy but automatically provides a soft white color. The initial cost is greater but the life of the bulb is expected to be 5 to 10 times longer and should pay off in the long run. Watch out for the low quality products which seem to cost 5 times less than good brands but in fact do not have the long life time at all. Good brands include the following:

  • GE
  • Feit
  • TCP
  • MaxLite
  • Sylvania
  • Westinghouse

3. Reposition The Light

Use a lower table for the lamp. For people who find the glare coming from the top, go for a higher table. But you might think about this too. The lamp was clearly designed in a way that makes the light come out strongly from the bottom. Why not exploit it and use this unique feature. Consider putting the table lamp high up, perhaps in the foyer of a house where the ceilings are high and so strong lighting is required to light up the entire place.

4. Make A Physical Alteration To The Lamp

Find a lamp repair shop which specializes in working with lamps. They will be able to create safely "inserts" that reduces the glare of the lamps. These are small, slats of plastic or metal material which block the light. Do not do this yourself unless you are confident in working with materials that are safe near a hot bulb. In particular, CFLs have internal circuitry which has a shorter life if the bulb is allowed to heat up more than the optimal specifications allow. By placing inserts around the lamp you are reducing the air flow, increasing the temperature, and potentially reducing the life of the CFL.

5. Buy Special Purpose, Half Chrome Bulbs

If you have downward projecting light bulbs in a glare-problem lamp, consider using a light bulb with half-chrome or chrome top bulb - these come in incandescents only. Instead of glass all around, the top hemisphere of the bulb is covered with a metallic coating to block light and diffuse it through reflection. All the above companies make this type of bulb in different wattages. Another reason to use a chrome top bulb (popular for chandelier shades) is that your lamp shade may not accommodate the substantial length of all but the shortest CFLs. These are also called half mirrored or half chrome mirrored. The cost is a bit higher (perhaps substantially higher from our brief survey) than normal bulbs, costing up to $2.29 to $10.96 per unit depending on the wattage and branding.
Here are three good sources for these special purpose products:

Measuring Glare

For the technically minded, glare is quantified through a (ironically somewhat subjective) measure known as the visual comfort probability or VCP. It is a scale from 1-100, the percentage of people, who find the light source comfortable from the absolute worst position in a room. According to the National Lighting Bureau (NLB), office spaces should have VCP scores of no less than 80 (70 in earlier years).

General Principles And Ideas To Reduce Glare

The tips above we gave are quite specific in the types of action to take. However, glare and brightness reduction is a general optimization procedure that follows a few principles. Most home and office spaces require lighting to be in some narrow band of optimality. If the light level is too low or too low - measured in foot-lamberts, fl or ft-L, the customary unit of luminance in the U.S. - then there is insufficient contrast and work becomes difficult. This may be due to the light directly (direct glare) or even indirectly (indirect glare). In the latter case poorly positioned windows, poorly angled computer screens give rise to inadvertent reflected glare.

  • Redirect the lighting using reflectors, louvers
  • Reduce the luminal output of the bulb
  • Reposition the light
  • Reposition the people, furniture away from the light
  • Change the orientation of the light or people
  • Move away home furniture elements that cause glare
  • Install screens, new shades to block the light more effectively