Participants in these studies wear a special sensor that uses spectroscopy to measure near-infrared light absorption; you see, red blood cells absorb light differently when they're carrying a lot of oxygen.

这些研究的参与者会戴上一个特殊的传感器，它使用光谱来测量近红外光的吸收；你看，红血球携带大量氧气时吸收光的方式不同。

Walls noted that many diurnal mammals had large corneas, fewer types of photoreceptor cells to see colors, and a tapetum lucidum—a reflective surface that increases light absorption by the retina.

Walls 指出，许多昼夜活动的哺乳动物都有大角膜、较少类型的感光细胞来识别颜色，以及绒毡层——一种增加视网膜对光吸收的反射表面。