Tucked away mostly unnoticed into the corner of your eye is small fold of membrane that serves practically no purpose ...

If evolution occurs through gradations, the critics say, how could it have created the separate parts of the eye -- the lens, the retina, the pupil, and so forth -- since none of these structures ...

Alternatively, students could explore the different parts of the eye. Given a diagram of the eye, students could be asked to add labels and annotation to describe the different parts.