When your eyes view an object, light reflected from that object is focused on the eye’s rod photoreceptors. However, because the rod photoreceptors cannot make the protein rhodopsin, the light cannot be converted into signals that are sent to the brain. This prevents us from seeing the image.
When your eyes view an object, light reflected from that object is focused on the eye’s rod photoreceptors, which uses rhodopsin to convert the light into signals that are sent to the brain. This allows us to see.