Yes, there can be double gravitational lenses. In such a scenario, the light from a distant source is lensed by two different massive objects, resulting in two distinct sets of distorted images. This can occur when the source, the two lensing objects, and the observer are all aligned in a specific configuration.

The effects of double gravitational lensing can be complex and can lead to various interesting phenomena, such as the creation of multiple images of the same source, magnification of the source's brightness, and distortions in the shape and size of the images. The properties and characteristics of the double gravitational lens system, such as the masses and positions of the lensing objects, the distance to the source, and the wavelength of the light, all play a role in determining the observed effects.

Double gravitational lensing provides an important tool for studying the properties of massive objects, such as galaxies and galaxy clusters, and for probing the nature of gravity and the large-scale structure of the universe. By carefully analyzing the observed distortions and image configurations, astronomers can infer valuable information about the mass distributions and the gravitational fields of the lensing objects.