there are different glasses for the different tvs , lg are using the passive glasses , similar to the ones you would wear at the cinema , the tv shows two images ..
sony , panasonic , and samsung , use active shutter glasses , that only work with tvs using the active system , the tv shows one image , then another , extremely fast , one for each eye , the glasses only let one eye see each image at one time , this happens so fast , that the brain creates the 3d image , but using this system , means you will be able to have real 1080p 3d , the former , passive system cant do that ..
all 3d tvs will work with sky 3d , which is
passive not
active , the active tvs will have to do a bit more processing to display the passive image , but it can be done ..
p.s. if there are one , or several mistakes in that info , forgive me , i only read it myself a few hours ago