摘要 |
A new lens system and method of use for otherwise conventional refractors comprising a synchronized, three-lens, variable crossed cylinder lens attachment and selectable fixed crossed cylinders which may be placed in the examining optical path. The synchronized, variable crossed cylinder lens attachment replaces the Jackson crossed cylinder lens and rotates in step with rotation of the cylinder lens axis. Batteries of strong and weak crossed cylinder lenses replace the strong and weak cylinder lenses of conventional refractors. Refractive techniques utilizing the disclosed crossed cylinder lens systems are also described.
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