Lens for eye-tracking applications and head-worn device

The present invention relates to a lens for eye-tracking applications. The lens comprises a first protective layer, arranged to face towards the eye to be tracked when the lens is used for eye-tracking. It also comprises at least one light source, at least partly arranged in the first protective layer, arranged to emit a first light from the first protective layer in a direction towards the eye. Moreover, it comprises at least one image capturing device, at least partly arranged in the first protective layer, arranged to receive the first light within the first protective layer. The lens further comprises an absorptive layer, arranged on the far side of the first protective layer seen from the eye to be tracked when the lens is used for eye-tracking, adapted to be absorptive for wavelengths of the majority of the first light.