in the case of the whales, whom returned to the deep sea 40-50mya and have since rarely had a use for visible light, it's interesting to wonder what they have e

in the case of the whales, whom returned to the deep sea 40-50mya and have since rarely had a use for visible light, it's interesting to wonder what they have evolved to care most about if no longer visible light, especially in the sense of their song, and when you compare the visual acuity of their cousins the dolphins in the same timespan, and the incredible hyper-evolution of the human eye since ~1mya