Almost exactly twenty years ago, I submitted the first two journal papers of my research career to IEEE Transactions on Microwave Theory and Techniques (MTT). These papers described my initial explorations of what later became known as the finite-difference time-domain (FD-TD) method for Maxwell's equations. The two papers, and the Ph.D. dissertation research that they reported, grew from a graduate seminar course at Northwestern University in bioelectromagnetic hazards that Prof. Morris Brodwin had conducted in 1972. During my independent study for this seminar, sought to obtain a model for UHF and microwave penetration into the human eye to better understand the formation of "microwave cataracts," which had been observed in a number of radar technicians during World War II. At first, there appeared to be no viable means to solve Maxwell's equations for the complex, three-dimensional biological tissue geometry represented by the eye, its surrounding muscle and fat tissues, and its embedding within the bony orbit of the skull.