91ɫƬ

Cats’ eyes in sight

The irises of domestic cats’ eyes are ovoid, but those of big cats such as lions and leopards are round like human irises. Why is this and do the differences confer any advantage either way?

John Neimer, Weymouth, Dorset, UK

We pay £25 for every answer published in New Scientist. To answer this question – or ask a new one – visit newscientist.com/lastword. Terms and conditions apply.

Topics: Last Word

More from New Scientist

Explore the latest news, articles and features