Barker F M
J Am Optom Assoc. 1984 Oct;55(10):753-7.
The effectiveness of multifocal correction upon presbyopic near and intermediate visual resolution performance was measured using Landolt ring targets. Decimal resolution acuity was determined at eight viewing distances from 36.4 cm to 1 m for non-presbyopic controls, presbyopic subjects corrected for infinity, and for presbyopic subjects corrected by bifocals, trifocals and Varilux 2 multifocal lenses. Non-presbyopic subjects demonstrated a resolution ability of 1.9 decimal acuity or better at all viewing distances. Presbyopic subjects corrected for distance but without multifocal addition showed a precipitous decrease in visual acuity to less than .50 decimal acuity at distances closer than 58 cm. When corrected by conventional straight-top bifocal lenses, these individuals regained a maximum of 1.8 decimal acuity at 40 cm, but demonstrated a significant depression of intermediate visual acuity to about .90 between 44 and 58 cm. Correction with straight top trifocal lenses and Varilux 2 progressive addition lenses enabled presbyopic subjects to resolve acuity targets at the level of 1.6 decimal acuity at all test distances.
使用兰多尔特环靶测量了多焦点矫正对老视近、中视觉分辨能力的有效性。对于非老视对照组、矫正至无限远的老视受试者以及通过双焦点、三焦点和Varilux 2多焦点镜片矫正的老视受试者，在从36.4厘米到1米的八个观察距离处测定了小数分辨视力。非老视受试者在所有观察距离下的分辨能力为1.9小数视力或更好。矫正了远视力但未增加多焦点的老视受试者，在距离小于58厘米时，视力急剧下降至小于0.50小数视力。当使用传统的直顶双焦点镜片矫正时，这些个体在40厘米处最多可恢复到1.8小数视力，但在44至58厘米之间的中间视力明显下降至约0.90。使用直顶三焦点镜片和Varilux 2渐进多焦点镜片进行矫正，使老视受试者在所有测试距离下都能分辨出1.6小数视力水平的视力目标。
