Answer:
By making other senses extra sensitive...
Step-by-step explanation:
It is away of nature that if it causes a defect in one things then make the other parallel corresponding thing a little more enhanced. Cave dwelling organisms lost their eyes our sense of vision but their sense of locomotion get enhanced by way of natural selection. Similarly tapeworms have developed an extensive absorption mechanism to replace digestive system. In case of mammals like whales they lost their limbs and adapted to marine environment. Whales developed fins and tail that help them to move better in aqueous medium. That how natural selection helps with species to adapt.