Jumping spiders & Eyes

Jumping spider eyes are incredible.

Jumping spider eyes are incredible. Their pair of central eyes, known as the principle eyes, are almost like a pair of tiny binoculars: They have a large outer lens, then a smaller inner lens that magnifies the image from the outer lens and projects it onto the retina. The spiders are also unusual in that they have muscles attached directly to their retinas. That means they can move retinas up and down, side to side, focusing on different segments of the world without a hint of movement on the outside,