What are two types of digestion animals use to break down and absorb food?

Two types of digestion: Extracellular and Intracellular. Extracellular is the digestive process that occurs outside the cells, ie outside the body. Intracellular is the process of digestion that takes place inside several cells in digestive vacuoles.

The sclera and cornea make up the exterior layers and the uvea is the vascular layer in the middle.