retinal

Concise Oxford English Dictionary © 2008 Oxford University Press:
retina /ˈrɛtɪnə/

▶noun (pl. retinas or retinae /-niː/) a layer at the back of the eyeball that contains cells sensitive to light, which trigger nerve impulses that pass via the optic nerve to the brain, where a visual image is formed.

– derivatives
retinal adjective,
retinitis noun.

– origin ME: from med. L., from L. rete ‘net’.