Flicker

• In order to maintain their lighting conditions, fluorescent lights must be used with a modulated cycle of electrical current. The fluorescent ballast conducts these modulations. Different types of fluorescent lights cycle at different frequencies. Those in the lower ranges, such as 60 hertz, can sometimes be perceived by humans as a "flicker" effect. Fluorescents at higher cycles, such as 120 hertz, do not usually cause this effect.
  
  

Flicker Problems/Solutions

• The light flicker is not permanently dangerous. However, the eyes are used to adjusting to lighting conditions, and the flickering confuses the eyes, sending constantly conflicting data to the brain. This may cause headaches, eyestrain, and general eye weariness. Electronic ballasts, a new version of the old fluorescent ballast used, can often decrease these symptoms in people who suffer from them.
  
  

High Heat Lights

• Fluorescent lights also range in the type of light they produce. Lower-end fluorescent lights produce warm white light, about 2,700K, a range that is easily absorbed by the human eye. However, fluorescent lights that produce hotter wavelengths of light are harder on the eyes. When light strikes the eye, certain cells undergo changes and send chemical reactions through nerve endings to the brain. These cells produce a small amount of waste as they work. As the light becomes brighter and warmer, these cells need to do more work and produce more waste.
  
  

Danger to Eyes

• As waste in the eyes accumulates, it can cause eye weariness and other general problems in normal eyes. In people with vision problems, especially those with eyes that have been damaged in some way in a previous accident, this buildup of waste caused by the bluish spectrum of fluorescents can be much more dangerous, leading to further damage of the eyes.
  
  

Detrimental Effects

• In addition to flicker and the workload placed on the sensitive cells of the eyes, scientists have conducted several studies that show fluorescent lights cause other problems. According to the H.E.S.E. Project, fluorescent lights have been linked to increased chances of melanoma cancer and even muscle weakness. Cool white fluorescent lights have also been pinpointed as a possible cause of mild child attention problems.