光反射 対光反射 瞳孔反射 瞳孔収縮 瞳孔縮小 縮瞳
reflex contraction of the sphincter muscle of the iris in response to a bright light (or certain drugs) causing the pupil to become smaller
動向を小さくさせる明るい光（または特定の薬薬物）に対応した虹彩の括約筋の反射収縮