I hesitate to recommend this technique for the reasons you mention. Do not try this at home. However, I have been doing this at many sites for 20 years and my eyes are checked regularly; there is no damage. The sun can be observed, indeed gazed upon, once the 'glare of the sky' is removed. The Solar Corona can be seen. My own research led me to this many years ago and the work of Professor North, of the University of Groeningen confirmed it. These little known optical qualities are on display at Newgrange, Maes Howe and Loughcrew. I would be glad to furnish a full explanation of the Optical Dynamics. The point is that Newgrange is now accepted as the oldest astronomically aligned structure in the world. Perhaps no longer.

David Kane.