Well, I cannot say if mine could be a viable solution, but since something like that happened to me some 15 years ago...
First of all, this is a management problem. I don't know how is the situation in your country, but here in Italy the work environment must respect some level of ergonomy. That's part of the legislation on workplace safety. Not complying could cost an employer a fine.
At the time I worked as a SW developer for a medium size research institution (~150 employees IIRC). I worked, together with other 5 or 6 colleagues, in an open space area all surrounded by glass walls in a position very exposed to sunshine.
There were blinds but they weren't very effective, even when completely shut. We had been complaining to management for about 6~7 months, but we received only vague answers.
It came the day when even some blinds broke (they were external to the building and somewhat exposed to weather), and the situation got fairly worse. Another month of complaints and nothing happened.
Then I did something you usually aren't entitled to do by usual internal network policy: I sent a mail to the internal broadcast address, i.e. I sent a mail to each and every member of the institution, management included!
This mail was written in a very informal (but neutral) tone, with the classic "internal info" format. It explained, citing several scientific and medical articles, the short and long term consequences of eye strain, glare and so on. In no way I mentioned the situation in our office. :-)
Some of those articles were also a bit scary (IIRC, they mentioned chronic retinitis or some other nasty eye-affecting syndrome), but they were very carefully selected and they came from extremely reputable sources (that is, they couldn't be dismissed as "paranoid" or urban myths, especially in an institution where almost 100% of the employees had a master degree and 50% a PhD!).
After two hours the IT manager called me in his office and mildly scolded me.
After two days the maintenance manager came to our office to examine the situation.
After a week we had some sort of cubicle walls installed that screened our work area and workstations from direct sunlight and glare.
After 10 days, top management sent us a mail in which they apologized for the "delays" in solving the issue and gave each one of us a ticket for a fairly expensive free lunch at the internal restaurant!
I don't know if this anecdote could help you, but sometimes simple complaints are not enough: you must "convince" the management that solving the issue is in the company's best interest.