So why don’t all vertebrates have this adaptation? It’s an advantage to animals that are active in the dark - cats, dogs, owls, raccoons, crocodiles, and so on - but it makes everything slightly blurry. Many daytime vertebrates (including humans and most other primates) do not have one and instead have better day vision.
Ever make a gif that is over 3MB and Tumblr won’t accept it? You want to make it smaller without affecting the overall quality? In this tutorial I go over a few methods that will allow you to decrease the file size of your gif without changing its appearance too much!