From early in life, chickens have good eyesight and can see quite clearly. Soon after they hatch, chicks are able to avoid obstacles, visually moving objects, and accurately peck at objects. They can also tell the difference between shallow and deep surfaces. Chickens attain peak sensitivity to spatial detail within 48 hours after hatching. In contrast, improvement in visual acuity takes weeks or months for kittens, monkeys, and human infants.