Determine if each light is necessary. Ask yourself what function each light fulfills. Every light should have a clear purpose. Is the light needed? How does it impact the area, including your neighbors, wildlife and the environment? Consider using reflective paints or self-luminous markers for signs, curbs, and steps to reduce the need for permanently installed outdoor lighting. Take the light out of service if it no longer serves a purpose.

Professional studies have shown lighting an unoccupied area can attract criminals. It is also a waste of energy. Turning off lights forces criminals to bring their own flashlights, causing them to be more noticeable if anyone is there to see them. It also allows wildlife to exist in the natural light of the stars and moon.  Timers, motion detectors, and half-night photocells can provide illumination, if needed, for an area or facility.

The human eye adjusts to the brightest light visible, and thus is ‘blinded’ to dimmer objects or areas. As a result, significantly less light than is the modern habit is best to enhance night vision. Remember that a very bright light will make surrounding unlit areas seem impossibly dark, and mask whatever is in them.

What you cannot tell from the “Better Lights for Better Nights” handout at the beginning of this application is the amount of light that each fixture produces. The amount of light produced is measured in lumens. Too many lumens (i.e. too bright a light) for a particular application will cause light to bounce off of the surfaces it shines on and reflect up in the sky, in the eyes of people trying to see nearby, into the habitat of nearby wildlife, etc. The light may draw in birds and insects that then will not be able to escape and proceed with their natural activities. Reduce the lumens (the amount of light) to let your eyes work as they should.

Did that just say lower the lumens? You bet. When you reduce the amount of light you not only cut the glare and allow people to see better, but by putting light only where it is needed you can get the same amount of usable light with about half the electricity cost of an unshielded light. That's a win-win!

Living things need light in the blue wavelength (white light) during the day, especially through the morning hours, but blue light should be avoided after dusk. With current technology, the best way to tell a light is blue-rich is to look at the color temperature of the light.  Warm colored lights usually produce less light in the blue wavelength. The color temperature of a light may be listed on the package just as 'warm' or 'cool', or the manufacturer may indicate the Kelvin(K) rating for a light. Old-fashioned incandescent bulbs are rated around 2700K, which is described as a warm color. Many of the bright white LEDs are rated at 4000K and above. Newer 3000K LEDs may be extremely blue-rich. These bright white, blue-rich light suppresses the production of melatonin in living organisms which can, over the long term, damage the health of that organism.

Know when a particular light will be used and take into consideration what the color of the light does to living things. Remember, blue light should be avoided after dusk. You may find it interesting to research the lighting studies led by Dr. George Brainard that focus on the type of lighting used inside the International Space Station and its effects on the astronauts.