Studies in chickens suggest low intensity ambient lighting causes myopia. The purpose of this experiment was to examine the effects of low intensity ambient lighting (dim light) on normal refractive development in macaque monkeys. Seven infant rhesus monkeys were reared under dim light (room illumination level: ~55 lx) from 24 to ~310 days of age with otherwise unrestricted vision. Refractive error, corneal power, ocular axial dimensions, and choroidal thickness were measured in anesthetized animals at the onset of the experiment and periodically throughout the dim-light-rearing period, and were compared with those of normal-light-reared monkeys. We found that dim light did not produce myopia; instead, dim-light monkeys were hyperopic relative to normal-light monkeys (median refractive errors at ~155 days, OD: +3.13 D vs. +2.31 D; OS: +3.31D vs. +2.44 D; at ~310 days, OD: +2.75D vs. +1.78D, OS: +3.00D vs. +1.75D). In addition, dim-light rearing caused sustained thickening in the choroid, but it did not alter corneal power development, nor did it change the axial nature of the refractive errors. These results showed that, for rhesus monkeys and possibly other primates, low ambient lighting by itself is not necessarily myopiagenic, but might compromise the efficiency of emmetropization.

对鸡的研究表明，低强度的环境照明会导致近视。本实验的目的是检查低强度环境照明（昏暗的灯光）对猕猴正常屈光发育的影响。七只婴儿恒河猴在昏暗的光线下饲养（房间照明水平：~55 lx），从 24 到~310 天，视力没有其他限制。在实验开始时和在整个昏暗饲养期间定期测量麻醉动物的屈光不正、角膜屈光力、眼轴尺寸和脉络膜厚度，并与正常光饲养的猴子进行比较。我们发现昏暗的光线不会产生近视；相反，昏暗的猴子相对于正常光线的猴子是远视的（约 155 天的中位屈光不正，OD：+3.13 D vs. +2.31 D；OS：+3.31D vs. +2.44 D；在 ~310 天时，OD：+2.75D 与 +1.78D，OS：+3.00D 与 +1.75D）。此外，昏暗的饲养导致脉络膜持续增厚，但它没有改变角膜屈光力的发展，也没有改变屈光不正的轴向性质。这些结果表明，对于恒河猴和可能的其他灵长类动物来说，低环境照明本身并不一定会导致近视，但可能会影响正视化的效率。