See through thermal curtains - do they exist?

[IsThisTheWaytoSlamMyPillow]

I have a very large “decorative” window in my hallway which is secondary glazed but still lets the cold in (and heat out) so it makes everywhere freezing!

Is there such a thing as a thermal or insulated curtain I can use which wouldn’t block the light but would keep heat in? I’ve tried googling and just got more confused!

Thanks - I’ll post in ‘chat’ too, for a bit more traffic.

No as the material required for it to be thermal is opaque.

Surely when you close the curtains it will be dark anyway,no light coming in. Blackout curtains are thick, often with a silver metalic Finnish.

Do you want to have them closed during the day? Thin cotton voiles might offer some (but not much) draughtproofing.