They also work as light buckets, but they only collect light through our pupils, which even under the best of circumstances are less than a centimeter across; a very tiny bucket indeed.

它们也相当于收集光线的水桶，但它们只是通过瞳孔收集光线，而瞳孔在最大的情况下，其直径也不到一厘米；只是一个非常小的桶。