منابع مشابه
Further evidence that chick eyes use the sign of blur in spectacle lens compensation
Young animals compensate for defocus imposed by positive or negative spectacle lenses by adjusting the elongation rate of their vitreous chambers, thus matching the length of the eye with the focal length of the eye's optics combined with the spectacle lenses. The ability to compensate for either negative or positive lenses could rely on the ability to distinguish between myopic and hyperopic b...
متن کاملPrescribing of Spectacle Lenses.
SIRS,-The attention of the Council of British Ophthalmologists has been drawn to the difficulty which the Services and the Ministry of Health are experiencing in obtaining spectacle lenses to supply their urgent needs, and it has been suggested that the situation could be helped by a simplification of the prescriptions supplied by civilian ophthalmic surgeons. LThe Council has considered the qu...
متن کاملUpdate on Spectacle Lens
Majority of the advances in spectacle lens continue to occur in the area of progressive lens design by most of the spectacle lens manufacturers. Since the introduction of progressive addition lenses (PALs) in 1959 by Essilor, it has gained worldwide acceptance for the treatment of presbyopia. While progressive lens design, manufacturing and dispensing techniques have grown at a good pace in the...
متن کاملAxial Performance of Spectacle Lenses
The measured values of the axial meridional powers for 311 spectacle lenses are reported. The spherical refractive powers range from + 7 . 0 0 to —20.00 diopters with cylindrical powers of 0.00, 1.00, and 2.00 diopters. The departures of the measured from the nominal values are shown. The probable errors of measurement are discussed. A set of tolerance values is suggested and the degree of comp...
متن کاملVascularity in the reptilian spectacle
sensitivity curve for 1° 200 ms. flashes on a white background may be a rather precise indicator of the functioning of the opponent-color system. Thus, although J. T. believed that his right eye was normal, the corresponding spectral sensitivity curve (continuous curve, Fig. 3) lies near the limit of the normal range, indicating that his right eye may have been partially affected by a similar d...
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ژورنال
عنوان ژورنال: Lung India
سال: 2013
ISSN: 0970-2113
DOI: 10.4103/0970-2113.120630