As the boat picked up speed, the coastline receded into the distance until finally it became invisible.
The police found traces of blood on his jacket that were invisible to the naked eye.
The infrared rays are invisible except when viewed through a special filter.
The discovery of the microscope in the late 17th century caused a revolution in biology by revealing otherwise invisible and previously unsuspected worlds.
In effecting its miraculous result, it is invisible and without substance.
They asked: were there really no girls in youth cultures and street gangs or had sociological accounts made them invisible?
