An eye-mountable device is provided that includes an eyelid occlusion sensor. The eyelid occlusion sensor is used to detect winks, squints, downwards glances or looks, blinks, or other eye-based gestures generated by the user. Based on the detected gestures, an optical power of an adjustable lens of the device may be changed or some other operations could be performed by the eye-mountable device. Such operations could include toggling the optical power of the lens between first and second power levels due to the user squinting, looking downward, or performing some other gesture. Additionally or alternatively, such operations could include setting the optical power of the lens to a first optical power unless the user is looking downward, in which case the optical power of the lens could be set to a second optical power.