The optical characteristics of aiming scopes in archery

Technical advancements in target archery have been extended to widespread use of "scopes" which magnify the target. In fact, these optical devices are simple converging lenses used at an arm's length from the eye. They produce a magnified image, but it is an image that suffers from significant dioptric blur, diminished somewhat by use of a peep sight in the bowstring which functions as an aperture stop. Visual acuities were taken with these scopes and, as might be expected, it was found that subjects saw no better with them. With the highest power scopes, acuity actually decreased. Experienced archers did slightly better with these aids than those with no archery experience.