Adult eyeworms live in the conjunctival sacs (space between the eyelid and the eye itself) and in tear ducts; small animals (dogs and cats) tend to have smaller conjunctival sacs, making them less ideal hosts.
While cats are not considered an idealhost environment for heartworms, and it is less common to see cases of heartworm in cats, it is still possible for cats to contract heartworms from mosquitoes.