Vision was thematically woven through my week in a number of interesting ways. Of course, my readings and lab work in cognitive psychology were central, but the topic was also featured in a book I’m reading for a neurobiology course, Incognito by David Eagleman, and sustained during a field trip to the Bodies Revealed exhibit in Lexington, KY on Thursday. Finally, the subject’s juxtaposition between neuroscience and medicine led me to investigate oththalmology for the first time, which, it turns out, is more interesting, diverse, and accomplished than I had guessed.
As of March 22, 2012, David Eagleman will be Berea College’s first neuroscientist convocation speaker in several years. In anticipation, Megan Hoffman is using his book, Incognito: The Secret Lives of the Brain as a book club-like supplement to her neurobiology course’s lab component. Chapter 2 of the book, called “The Testimony of the Senses: What Is Experience Really Like?”, focuses on vision’s marvels and limitations to identify and emphasize the fundamental barrier between each of us and the external world. He uses Mach bands, change blindness, Yarbus’ eye tracking studies, multistable stimuli and perceptual switching, Mariotte’s blind spots, Helmholtz’s unconscious inference, optical illusions, and striking case studies to support the unavoidable conclusion that the brain generates an imperfect, biased, and therefore unreliable model of reality from our senses, vision most of all.
On Thursday morning, the biology department sponsored its neurobiology course’s field trip to the Bodies Revealed: Fascinating + Real exhibit in Lexington, KY. The exhibit uses polymer-preserved human specimens and is organized along the common “systems” medical school curriculum approach, beginning with the skeletal and muscular systems, followed by the auditory, visual, and nervous systems, then the endocrine, circulatory, respiratory, alimentary, reproductive, and urinary systems. There was also a room dedicated to fetal development. I was particularly interested in the nervous system section, where the brain, spinal cord, peripheral components, and sensory organs were featured. And while startling complexity is apparent even at the gross anatomical level and has been recognized for centuries, the brain’s true marvels remained hidden until light microscopes allowed glimpses of its organization and interconnection at the cellular level. This cellular scale was hinted at in representative prints throughout the exhibit, but wasn’t incorporated into the specimen displays themselves, though to be fair, it’s hard to imagine how this could have been accomplished easily or effectively.
Finally, all this attention to vision made me realize that I knew very little about the clinical medical specialty devoted to it. Ophthalmology, “the science of the eyes”, is a medical and surgical specialty that seeks to prevent or treat diseases of the eye and surrounding anatomy. The most common maladies of the eye include cataracts, glaucoma, retinal disorders, refractive errors, macular degeneration, diabetic retinopathy, amblyopia, strabismus, and nystagmus. But as we know, the eyes don’t do the seeing, they only collect light energy for the brain to translate. Damage to or diseases affecting the brain’s visual centers may instead be treated by neurosurgeons (when treatment is possible). One particularly interested area in which technological innovation and convergence between ophthalmology and neurosurgery is rapidly advancing is brain-machine interfacing. Whether by camera implants or sensory augmentation, many blind people will, in the coming decade, become sighted, though unfortunately, perhaps only those that can afford the technology directly or the insurance that covers it.