Nicholas Roerich wrote in "Heart" these words of El Morya: "Surya-Vidya [solar science] - thus was the Teaching of the Heart sometimes called. In this definition was indicated the fieriness, the sun-like quality, the centrality of the heart."
I think that it's important to remember that we have a sun in the center of our hearts, and that we can do inner sungazing, if for some reason we can't do outer sungazing. Also, inner sungazing will remind us of the purpose of sungazing - to become like the sun, so we don't get caught up in gaining powers through studying the outer surya vidya or science of the sun. I'm not talking about heliophysics, but an arcane science that is taught to initiates in the Himalayas. Yogananda wrote about one of these initiates, Vishhudananda, in his autobiography in the chapter on the perfume saint who was able to manifest any scent by focusing the rays of the sun on a person's hand with a lens. He also was able to bring a dead bird back to life by focusing sunlight in the bird's eyes. He did many experiments, but never taught anyone what he knew. Another student of the science of the sun was Gene Savoy, who also experimented with lenses and discovered that the sun had various types of rays that had specific effects on the body and mind. He kept his knowledge secret and passed it on only to select initiates of his church, but some of this information was made public by Dr. Mitchell Gibson, a student of Savoy. He gave me permission to reprint an article he wrote about this in the Spring, 2009 issue of The Sun Gazette, which you can read at http://www.angelfire.com/.../isisaz/SUNGZET8.pdf
Another researcher who experimented with sunlight and lenses was the psychologist Gustav Fechner, who developed celestial vision. He was visited by Kuthumi in 1850. Fechner should have been given the title of Father of Psychology, but because of his strange theories, he was rejected by the scientific community.