At the moment, no, sorry :/ (but as JD said, putting it into night mode and using green works, but that however gets rid of any backgrounds you may have, at least it does for my 920).
Thank you. I also have a 1020, and Glance clock is so much brighter on that; it just seemed odd that the 1520, even in green, is not as clear. I can't help feeling that the difference in brightness between the phones is significantly worse, even though the 1520 is the 'nrwer' phone.