I'm not as against "it was" as some, but I can't see what benefit you get here by using that rather than just "They came on..."
I think I'd like a new paragraph after "The came in silence." I think it would somehow add more gravitas to those opening sentences.
The first thing that really stopped me was "the white pierced the darkness" What is the reader supposed to be picturing here? The white what? After that I got a little lost--"sent" is more often than not a very weak word to use; in what way does the sunlight send him to the ground? And how?
"overloading of the senses as he covered his face with one hand" Sounds a little strange to me, almost as though there is a tense shift there. Also, his "senses" are overloaded and yet they came in silence? And you haven't mentioned any smell, so really is it just his sight that is overloaded rather than all his senses?
groping in the brightness of confusion A bit nitpicky, but if a tent had just disintegrated about me, I wouldn't be sticking my hand out there. What is he groping for? I think I'd just curl into a ball or something.
and cries of his people, calling out, not sure you need that comma after "people".
Excellent last sentence
I must admit I wasn't hooked until that last sentence--it just seemed a little rushed and distant, nothing to really connect to, and I was unsure how he had lost all his senses. I think the loss of his sight worked very well, losing the other senses didn't seem to add to the story anything other than confusion.
If you don't mind waiting possibly over a week for the crit, feel free to send it over.