These Sony 3D glasses represent a significant step forward from the previous two iterations from Sony. The `original' 3D glasses from 2010 - Sony TDG-BR100 Adult Size 3D Active Glasses, Black
- are extremely bulky and uncomfortable plus they require a battery to work. In 2011 Sony improved their glasses making them rechargeable from the TV and a bit lighter - see Sony TDGBR250 Rechargeable 3D Glasses
- but they still are pretty uncomfortable and bulky. The new glasses are frameless and much lighter - rather like sunglasses. Like the 2011 version they are rechargeable so there's no need for a battery, and they charge very quickly indeed. While they are not quite as comfortable as ordinary glasses - they sit rather high on your face, I assume to allow space for users to wear they normal prescription glasses - they are a massive improvement.
An added bonus is that the glasses work with all previous Sony TVs. I also found that crosstalk was a little reduced although it's possible that I'm imagining this as the TV remains the same! While more expensive than the other 3D glasses Sony have produced, I'd expect the price to fall. The original glasses cost in excess of £100 but prices have come down. Certainly if you're thinking of replacing existing glasses, or buying them for the first time, as someone who has all three types, I'd really recommend these notwithstanding the cost.
Five stars for a remarkable advance in technologies.