To prevent people with diabetes from having to prick every day, they look for simpler techniques to know glucose levels. In this sense, you can have lenses that vary in color depending on the glucose level. Thus, red indicates hypoglycemia and violet hyperglycemia. If the blood glucose level is adequate, the contact lenses will be green.
It is said that along with the lenses a small mirror will be distributed that will have a color table to compare with the color of the lenses. The University of Pittsburgh has just patented the technology and will be ready to test in humans every year.