Eye diagram unlabelled (blown up to A3) given to each group, with a set of label cards. First use prior knowledge to label the diagram - assessing prior knowledge.
Then move around the room collecting information on the structures of the eye, filling in the worksheet. Return to group, and use this information to have another go at labelling the diagram. Excellent means of showing progress.
Move on to each label their own diagram, and discuss rods/cones - linking back to previous lesson on the Nervous system.