Final answer:
The choroid layer of the eye prevents light from scattering inside the eye and provides a blood supply to the retina.
Step-by-step explanation:
The function of the choroid layer of the eye is to prevent light from scattering inside the eye. The choroid is a layer of highly vascularized connective tissue that provides a blood supply to the eyeball. Specifically, it supplies the outer retina with blood. It is part of the vascular tunic, located between the sclera and the retina. The choroid aids in absorbing excess light within the eye, ensuring that this light does not cause scattering that would lead to blurry vision.