'Smart' window switches to dark mode to save energy (BBC)

[eppur_se_muova]

A new type of "smart" window that switches from summer to winter mode has been made by South Korean scientists.

The window darkens when the outside air temperatures soar, and becomes transparent when it gets cold in order to capture free heat from the sun.

Similar windows already exist, but the researchers say their method allows for an almost instantaneous switch from opaque to transparent.

This may help save more energy, the team writes in the journal ACS Nano.

"This type of light control system may provide a new option for saving on heating, cooling and lighting costs through managing the light transmitted into the interior of a house," said the scientists.
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more: http://www.bbc.co.uk/news/technology-15076773

[Drale]

1. It sounds like it works in a similar way to the

transition lens they have for glasses.

[binarysunrise]

2. lenses?

Surely it's not that simple.

And it makes me wonder:
1) how many times more will this cost than regular glass?
2) how do you get even window tinting? (assuming all of the room/house isn't at the same temperature)
3) what happens if you wanted to look outside, and you're stuck with dark windows?