Eikonic Lens Design for Minus Prescriptions
作者:
GREGORY GOOD,
MICHAEL POLASKY,
期刊:
American Journal of Optometry and Physiological Optics
(OVID Available online 1979)
卷期:
Volume 56,
issue 6
页码: 345-349
ISSN:0093-7002
年代: 1979
出版商: OVID
关键词: aniseikonic corrections;shape factor;power factor;lens design;eikonic eyewear
数据来源: OVID
摘要:
Designing size lenses for aniseikonia correction usually involves considering only the shape factor of the total spectacle magnification. However, for minus prescriptions, an increase in the shape magnification of a lens does not always result in total lens magnification. As the front curve of a lens is steepened (which increases the shape magnification), the sagittal depth of the lens is increased, which effectively increases the vertex distance. For a minus lens, an increased vertex distance means decreased power magnification; depending upon the lens power, the decrease in power magnification can totally offset the increase in shape magnification. The shape factor-power factor relationship of high minus size lenses is presented, along with general guidelines for proper design of size lenses.
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