Maybe optical coatings are so much better now that they cut much of the
glare, but when my husband and I were involved in amateur astronomy about 20
years ago, we were told never to look at the full moon through a telescope
without using a filter, and not just to cut glare so features showed up
better. The terms I am seeing on astronomy websites now are "discomfort" and
"like shining a flashlight in your eyes." Maybe I am more sensitive to
bright light than most, but if someone shines a flashlight in my eyes, it is
so bright that my eyes hurt. 

 

So I stand corrected, but l'll bet that if you did use a filter, you'd be
able to watch for longer periods with less discomfort.

 

Pat Valdata

Elkton