Having had a search online I can now tell you that Sunglasses at Night is part of the Orly Flash Glam FX Collection, a range of glitters Orly brought out about 18 months ago. I just found it in TK Maxx (£4.99, bargain!)and thought it was pretty so had to buy in. :)
These pictures are two coats over a black base. It's horrible to photograph and the ones I took just don't do it justice, the bottle shot below gives you a better idea of what it looks like, a sheer grey black base jelly packed full of holographic bar glitter.
In regular light it isn't amazing but under bright indoor lighting or in sunshine (I'm guessing, we're about 5 months off seeing sunshine in Glasgow at this time of year) it really comes alive and is super sparkly and holographic.
It applies nicely, with the usual notes about trying to avoid any of the bar glitter hanging over the edges of your nails as it'll feel rough, and two coats over an opaque base gave a properly sparkly and rather 3D looking effect.