Deep cell parabolic lenses are used for two reasons. Compared to standard
acrylic lenses on fluorescent fixtures, they reduce glare. This is especially
desirable when computer video displays are used in a space, but is generally
preferred because it reduces eye strain. These lenses are also more efficient.
A three tube fixture with a deep cell parabolic lens produces as much light
as a four lamp fixture with an acrylic lens. This translates into reduced
Deep cell parabolic lens are 2 1/2 to 4 inches deep. They are made of
polished aluminum parabolic reflectors on a grid of about six inches each
way. Many newer buildings may provide these lenses as "building standard."