Question

practice 17
structure in the eye that focuses light rays on the retina
viewfinders
sensors
lens
mirrors
filters

Explanation:

In the eye, the lens is the structure that focuses light rays onto the retina. Viewfinders are not part of the eye. Sensors in the eye (like rods and cones) detect light, not focus it. Mirrors are not present in the eye for this function. Filters also do not focus light onto the retina.

Answer:

lens