At the recent meeting of the American Medical Association delegates, a number of topics were covered including the problems caused by nighttime light exposure and suggestions for minimizing those problems. According to the AMA and a number of studies, being exposed to light from any source during the evening and night hours create unsafe driving conditions and may cause other serious problems including certain cancers, weight gain and even brain impairment by decreasing memory skills.

Unshielded light at night, including the lights from other drivers could cause serious problems that might increase the number of traffic accidents. At dusk, or shortly after, the human pupil starts to dilate to allow more light in for better vision. The light from an oncoming car, though will cause the pupils to rapidly constrict as a means to protect the eye from damage however that also lowers the vision. The AMA suggested that new lights or shields on existing lights will allow light to be directed toward the ground instead. More research will be used to look at other effects that nighttime light has on the body's internal clock, called the circadian rhythm.

On a related note, animal studies have shown that exposure to light around the clock may cause an increase in risk of certain cancers. Light at night and/or waking often during the night may increase the risk of breast cancer. Theories suggest that it is a decrease in the production of melatonin, which is produced during sleep, that may increase cancer risk because the hormone may delay the speed of cancer development. Those studies prompted the International Agency for Research on Cancer to list working the night shift as a potential carcinogen.

In another study, light during the nighttime hours was linked to overeating and weight gain. Researchers think that it might again be melatonin that causes someone who does not get enough sleep to eat as many as three hundred extra calories the following day, but no exact reasoning was found. Weight loss efforts are often slowed by not getting enough sleep. The average person needs between seven to ten hours of sleep nightly to be at their best health.

The AMA recommends that people keep to regular sleep patterns and that they minimize exposure to light as much as possible. Those recommendations are for all age groups, including children who should sleep in dark rooms with only a dim, red colored light if they are afraid of the dark.