Beware though.. I got these once for a gift and had to return them. The effect was truly awesome BUT they left my eyes burning after no more than 10 minutes. I imagine much more exposure than 15 min at a time could cause permanent eye strain or damage.
Perhaps this is just my eyes, but be careful in making your decision please.
To compare my eyestrain level to yours, I can typically endure staring at a computer screen for hours on end, but playing Quake 2 (the colors in that game are freaking monotone, I dunno if that's why it does it) I can only take about 45 min max of playtime.