First Design of a Contact Lens for Diagnosis of Dehydration.

Dehydration is a serious medical problem for elderly patients and young children. The most widely used diagnostics are measurements of sodium ion (Na⁺) and potassium ion (K⁺) in blood serum. Dehydration is difficult to diagnose even by trained health care professionals because the body compensates to maintain the appearance of skin. These measurements required a blood draw because specific tests are generally not available for only Na⁺ and K⁺. The blood samples are analyzed by an electrolyte panel (EP) or a basic metabolic panel (BMP). Most hospitals limit EP and BMP to one per day to control costs. More frequent measurements of Na⁺ and K⁺ are needed, especially during rehydration. We designed a dehydration contact lens that can provide the Na⁺ and K⁺ concentrations as needed or for continuous monitoring. The measurements are obtained from the fluorescent lifetime or wavelength-ratiometric intensities of the Na⁺- and K⁺-sensitive fluorophores. The dehydration contact lens does not contain electronic components and are inexpensive to prepare.