Classroom demonstration of the visual effects of eye diseases.

An understanding of the visual system is a fundamental aspect of many neuroscience and psychology courses. These classes often cover a variety of visual diseases that are correlated with the anatomy of the visual system, e.g., cataracts are caused by a clouding of the lens. Here, we describe an easy way to modify standard laboratory glasses/goggles to simulate the various perceptual deficits that accompany vision disorders such as astigmatism, cataracts, diabetic retinopathy, glaucoma, optic neuritis, posterior vitreous detachment, and retinitis pigmentosa. For example, when teaching about cataracts, students can put on glasses that mimic how severe cataracts affect one's vision. Using the glasses will allow students to draw connections between the disorder, its perceptual deficits, and the underlying anatomy. We also discuss floaters in the eye and provide an easy method to allow students to detect their own floaters. Together, these demonstrations make for a more dynamic and interactive class on the visual system that will better link diseases of the eye to anatomy and perception, and allow undergraduate students to develop a better understanding of the visual system as a whole.