Multifunctional transition and temperature-responsive contact lenses

Abstract

Smart contact lenses have recently gained traction due to their functionalization as noninvasive diagnostic and therapeutic wearables that can address several ocular diseases. Herein, multifunctional contact lenses exhibiting UV-transition and temperature-responsive capabilities were developed utilizing chromogenic materials that were integrated simultaneously into poly(2-hydroxyethyl methacrylate) (pHEMA) contact lenses. The functionalities of the contact lenses were optically evaluated in both their activated and non-activated states. Transition contact lenses offered excellent UV and blue light blocking capabilities (~45%) at their inactive states. When activated via UV exposure, the transparent lenses darkened instantaneously and absorbed portions of the visible light spectrum. The absorption intensity and transient discoloration of the transition lenses relied primarily on the utilized photochromic material. Likewise, the temperature-responsive contact lenses exhibited distinct colorimetric variations in response to temperature changes within the physiological range (33–38 °C). The maximum sensitivity of the thermochromic lens was 8% transmitted light per Celsius degree shift. Physiochemical and morphological analysis indicated the adequacy of the contact lenses. Hence, the multifunctional contact lenses can be deployed as smart wearables to manage ophthalmic deficiencies that are deterred by UV radiations and variations in ocular surface temperature.

Effect of Light Sources on Transmittance of Commercially Available Contact Lenses

“…To ensure good eye health and quality vision, contact lenses should have low UV transmittance and high visible light transmittance. Contact lenses are multifunctional biomaterials that interact with various system environments [ 10 ]. In recent years, exposure to artificial lights, such as LED lamps, has significantly increased, which may have deleterious effects on most eye tissues [ 11 ].…”

Smart Contact Lenses for Healthcare Monitoring and Therapy

“…The colorimetric method can also be applied to the detection of ocular temperature and glucose concentration in tear fluid. Salih et al prepared bifunctional contact lens sensors with UV protection and temperature response using photochromic and thermochromic powders . The fabricated contact lenses were able to be activated under UV irradiation, and the activated lenses darkened and absorbed part of the visible light to protect the eyes.…”