A window is an opening in an otherwise solid, opaque surface, through which light can pass.

Glass is used to provide light and allow vision through otherwise opaque surfaces.

The three ramps led straight down into the pool and disappeared beneath its opaque surface.

They look like dull pieces of glass, with a milky, opaque surface.

His faceshield was down, presenting an opaque surface to the outside world.

At night, the cube is wrapped and the opaque surface becomes a projection screen.

Made from a mixture of oil paint and beeswax, it has a particularly opaque surface.

Thin tracks of blue veins run beneath its otherwise opaque surface.

"Smooth as glass," he commented, looking at himself reflected in the opaque surface of the building itself.

There were at least a dozen others as well- crowded around a long, low table with an opaque black surface, talking to each other.