PEP FBL
LIGHT-EMITTING-DIODES
Visible-spectrum LED's (light emitting
diodes) were developed from 1962 on in
the main colours red, orange, yellow and
green. It was only in the 1990s that
production of effective blue, green-blue
and white LED's became possible. This
triggered the development of small,
battery powered light boxes like the PEP
FBL on display here, that could be worn
underneath a visor or a hat in order to
fight for instance Seasonal Affective
Disorder or SAD. The peak emission of
this kind of devices was mostly between
green and blue, which is around 500 nm.
