A variable focus (10) lens comprising a fluid chamber (12) containing a first fluid (14) and a second fluid (16) is disclosed. The fluids are non-miscible and in contact over a meniscus (18) and the second fluid is able to alter its shape on the influence of a magnetic field. The second fluid is preferably a ferrofluid. Means (20, 22) for applying a gradient magnetic field (24) over at least a part of the fluid chamber are provided that are capable of inducing a magnetic flux maximizing movement of the fluids, such that the shape of the meniscus varies in dependence on the magnetic field.