People with glaucoma could be treated in the future with innovative contact lenses that monitor the condition of the eyes.
The "smart" contact lenses have been designed by Tingrui Pan and Hailin Cong, two researchers at UC Davis.
They contain pressure-sensing technology that can detect static or changing levels in the eye and transmit the data to a computer.
Photographs of the contact lenses show a patterned surface where the sensors are located.
Glaucoma - which can run in families - is the second leading cause of blindness globally, according to the World Health Organisation.
by Martin Burns