L&T: RxPertise   Chromatic Aberration: The End of the Rainbow
Photograph by Ned Matura  At the end of the rainbow is a pot of
gold, and over the rainbow is where bluebirds fly, or so they
say. Pots of gold and bluebirds aside, rainbows are generally
unwelcome visitors when it comes to your patients’ spectacle
lenses and retinal images.  It is rare that a patient will
actually mention the colored fringes or “rainbows” caused by
chromatic aberration. Much more common comments are, “I can’t
see with these,” or “These lenses are just not right.” It’s
frustrating to you as an eyecare provider, and disappointing to
your patient when aberrations of any kind interfere with the
performance of new eyewear.  The effects of chromatic aberration
result from a combination of the Abbé value of the lens
material, the prescription, the point at which the patient’s
line-of-sight intersects the lens and the distance from the
object being viewed.  Ophthalmic lens materials bend light by
slowing it down. The amount of slowing (a