41. The first one features an integral carrying handle with a built-in rear diopter sight and a folding front sight. 42. High PRA values ( > or = 3.50 diopters ) are considered to be diagnostic of disorders involving accommodative excess. 43. The actual power, as read by a vertometer or lensometer, might differ by as much as 0.1 diopters . 44. The diopter is an aperture sight component used to assist the aiming of devices, mainly firearms, airguns, and crossbows. 45. For example, to change refraction by 4 diopters with an optical zone of 3 mm would require ablation of 12 ?m. 46. :The diopters given as a lens prescription is the reciprocal of the focal length of the lens, measured in meters. 47. The archaeological record is full of such devices; simple inclinometers and diopters and sighting tubes extend through to ancient Sumerian times. 48. You may then need glasses of lower diopter , say-1 / 2 with a small cylindrical correction for optimal viewing. 49. No patient in the small-incision group had a worsening of astigmatism greater than one diopter , a measure of visual acuity. 50. The rifle uses a " peep " diopter sight, which is flipped over to reveal the open tritium enhanced rear night sight.
