摘要 |
<p>The invention relates to a variable-focus lens (60) for focussing light rays in light paths passing through the lens along an optical axis (”). The lens comprises an arrangement of first and second immiscible liquids (67, 68) that have different refractive indices and are in contact over a moveable refractive optical interface (69), a volume of gas (72) in contact with one of said liquids, and a retention measure (70, 74) for keeping the volume of gas away from the light paths of the light rays passing through the lens for focussing.</p> |