Dr. Glen Jeffery

You can't buy classic incandescents.

They're gone.

I think I signed a petition to try and keep them about six months ago, and I don't know what the status of it is now.

You should still be able to get halogen bulbs, which are almost identical to incandescent.

They're a type of incandescent.

And the point here is that you can't have...

LED lights in ovens because they melt.

So generally incandescents are retained for a few special reasons.

The importance of these I think is highlighted by something that should come out just before Christmas, one of our studies where at University College London we have some buildings without windows.

and they've got some pretty harsh LED lighting in them.

And what we did last year with those is we went in there and we measured all the people, the staff in there, we measured their ability to detect color,

Then we gave them a whole series of desk lamps, 40-watt incandescent desk lamps.

And we said, you don't have to look at this.

Just move around.

You know, if that's on your desk.

But a lot of them were architectural model makers.

So they'd be sitting at their desk for a little bit of the time.

Then they'd be going off gluing two bits of wood together.

Where's the light directed for these people?

Just directed down, not at their eyes.