Norton Thomas T
*PhD Department of Vision Sciences, School of Optometry, University of Alabama at Birmingham, Birmingham, Alabama.
Optom Vis Sci. 2016 Sep;93(9):1049-51. doi: 10.1097/OPX.0000000000000917.
: Human studies have provided strong evidence that exposure to time outdoors is protective against the onset of myopia. A causal factor may be that the light levels outdoors (30,000-130,000 lux) are much higher than light levels indoors (typically less than 500 lux). Studies using animal models have found that normal animals exposed to low illuminance levels (50 lux) can develop myopia. The myopia and axial elongation, produced in animals by monocular form deprivation, is reduced by light levels in the 15,000 to 25,000 range. Myopia induced with a negative-power lens seems less affected, perhaps because the lens provides a powerful target for the emmetropization mechanism. Animal studies suggest that raising the light levels may have their effect by increasing retinal dopamine activity, probably via the D2 receptor pathway, altering gene expression in the retina and reducing the signals that produce axial elongation.
人体研究提供了有力证据，表明户外活动时间可预防近视的发生。一个可能的因果因素是，户外的光照水平（30000 - 130000勒克斯）远高于室内光照水平（通常低于500勒克斯）。使用动物模型的研究发现，暴露于低光照水平（50勒克斯）的正常动物会发展为近视。单眼形觉剥夺导致动物出现的近视和眼轴伸长，在15000至25000勒克斯的光照水平下会减轻。用负透镜诱发的近视似乎受影响较小，可能是因为该透镜为正视化机制提供了一个强大的靶点。动物研究表明，提高光照水平可能通过增加视网膜多巴胺活性发挥作用，可能是通过D2受体途径，改变视网膜中的基因表达，并减少产生眼轴伸长的信号。
