I spend a lot of time staring at a screen most of it due to work and I get a lot of eyestrain and headaches and I'm wondering if these might help me at all and I have a couple of questions if anyone knows about these or has experience with them mainly: Are they a scam? Is there a significant difference? Some are yellow or even red whilst others appear clear what's the deal with that? Should I just get the cheapest ones is it just the frame quality and brand that affect pricing? Any help's appreciated!