[xystridura (David)]

I recently bought the above item; the day it arrived I happened to be going to the optometrist for a new pair of glasses, so while I was there, asked the technician if she could clean it for me.
She did so and at the time it looked good, but half a day later it had a semi transparent, crinkly appearance when I looked through it.
The graticle is still OK, the problem appears to be on the other side of it.

Help please!