They aren't. 23 grams is not heavy and that's the weight of one of their latest pairs of glasses.
Possibly. I would take the glasses to a TV store and try them. Samsung changed their 3d sync technology last year, so it may not work.
No, Samsung glasses are active and therefore are very different from LG glasses. LG uses the lower resolution FPR technology based on cinema 3D from two decades back so their glasses are totally different to Samsung. And finally, I'm not sure if 3D glasses have ever been remotely close to being trendy?
Active 3D glasses require batteries and had a reputation for being heavy. Modern glasses weigh in at as little as 23 grams (under one ounce) so they are not heavy. At under $20 per pair for some active glasses, they aren't expensive either.
LG televisions use passive glasses so you will not find LG active glasses. Actually, LG has made several models of active 3D televisions, despite their current push for passive. LG glasses such as the AGS100 will not work with Samsung televisions. If you are looking for lower priced glasses for your Samsung TV, try the Monoprice website.
Currently, all 3D televisions need glasses but the latest one are now only a few grams in weight. Active glasses are almost as light as passive glasses so there is no need to put up with the reduced resolution of LG passive 3D just to get light glasses.
They will only work with certain brands, namely those who use passive 3D technology. If you have a Samsung 3D TV, the movie theater 3D glasses won't work. Samsung 3D sets use battery-powered glasses and can only be viewed with their glasses.
For the 3DS, the 3D feature does not require 3D glasses to play so you do not need to buy 3D glasses.
You experience a headache because its Shutter glasses 3D TV. It works by sending both images into left and right eye rapidly one at time, which can cause headache and nausea. The shutter glasses also have power batteries in them which make them heavier than the glasses for Cinema 3D. Cinema 3D TV uses polarized 3D glasses just like the theaters so they provide the most natural way to view 3D images resulting in less headaches.
Check batteries in the glasses and make sure the glasses are properly paired to the television. Make sure they are set up according to the manufacturer's instructions and the flicker is likely to be eliminated.
Battery free glasses for 3D are better if they are being used with passive 3D televisions. LG only have passive 3D television so the battery free glasses work with them. The other premium brands such as Samsung, Sony etc all use active 3D and their glasses are battery powered. The active glasses are far better for use with active televisions because the battery free glasses won't work with them. Previous criticisms of active glasses were weight and battery life. With the weight below one ounce and battery life of over 100 hours, neither of these are issues any more.
Most Sony 3D users would argue that the glasses are not uncomfortable. Before buying a 3D television, it's worth experiencing the glasses to confirm that they are comfortable.
Active glasses and passive glasses use very different technologies to separate the left and right eye images. To choose a 3D television based on the type of glasses is not a wise decision. Spend time to study both active and passive images. Experience a range of models and get a feel for the difference in the glasses. Make your choice based on which image is the best, which glasses are most comfortable and which 3D image looks the most realistic. Remember that active glasses are now as light as passive glasses so there is rarely an issue with heavy glasses now.