A natural convex lens present in an eye is called crystalline lens.
The lens is also known as the aquula (Latin, a little stream, dim. of aqua, water) or crystalline lens. In humans, the refractive power of the lens in its natural . The crystalline lens of the eye is a natural lens which produces one third of the eye's total optical power and focuses light into an image on the retina (the light-sensitive tissue at the back of the eye). The crystalline lens is elastic which allows it to flex in order to change its shape.
The crystalline lens is the name given to the natural lens that humans are born with. Small muscles attached to the lens can make the lens change shape, which allows the eyes to focus on near or far objects.The lens capsule is a smooth, transparent basement membrane that completely surrounds the lens. The capsule is elastic and is composed of collagen. It is synthesized by the lens epithelium and its main components are type IV collagen and sulfated glycosaminoglycans (GAGs).
The crystalline lens is a transparent, biconvex biological lens located in the eye's posterior chamber. It is attached to the sides of the eye by the zonule of Zinn or suspensory ligament of the crystalline lens, which extends from the equator of the crystalline lens to the ora serrata.