Here's my info:
When light strikes the retina, the photoos pass through the layer of ganglion cells, then the bipolar cells, then the rods and cones. In the rods, the rhodopsin absorbs light, causing the retinal part of the molecule to change shape. This in turn causes a change in the shape of the opsin molecule.
This change in the opsin activates a relay molecule called transducin. This ensures less inhibitory neurotransmitter is released into the synapses so an electrical impulse can be transmitted between the rods and bipolar cells, and then between the bipolar cells and ganglion cells. The ganglion cells extend into the optic nerve fibres, which transmit the electrical impulse to the brain.
The opsin and (changed) retinal recombine to form rhodopsin.