Contact lenses are an excellent invisible aid to
vision. Eye care practitioners usually fit either a soft or a
gas-permeable
(GP) contact lens for the management of an error of refraction (myopia,
hypermetropia, astigmatism, or presbyopia). But, in some ocular conditions like
keratoconus (conical cornea), wherein spectacles and routine contact lenses do
not provide the needed help in improving vision, eye doctors may, sometimes,
resort to the fitting of a piggy-back system, whereby a GP lens rests on top of
a soft contact lens, resulting in comfortable improvement in vision. (
The
picture from Times of India dated July 23, 2014 shows a koala cub riding on its
mother’s back at a zoo in France).
Dr. Narendra Kumar
