hard to see

See: obscure
References in classic literature ?
I know there are many people going about who tell such plausible stories that it is very hard to see through them, but there is a style about your language which assures me of your good disposition.
As to the inside, all the walls, instead of wainscot, were lined with hardened and painted tiles, like the little square tiles we call galley-tiles in England, all made of the finest china, and the figures exceeding fine indeed, with extraordinary variety of colours, mixed with gold, many tiles making but one figure, but joined so artificially, the mortar being made of the same earth, that it was very hard to see where the tiles met.
Regardless of that controversy, Cotto is a world-class monster and it is hard to see former British champ Jennings finding a way past him.