VAT PHOTOPOLYMERIZATION 3D PRINTING OF MULTIFUNCTIONAL CONTACT LENSES FOR OCULAR APPLICATIONS

Smart contact lenses offer unique opportunities as personalized, non-invasive devices that simultaneously perform a wide range of functions. However, the actual production of smart contact lenses is rather challenging. Herein, two vat photopolymerization 3D printing techniques are presented for producing multimaterial and multifunctional contact lenses. In the first technique, a contact lens is 3D printed with hollow channels, which are later filled with resin containing different dyes or drugs. In the second method, functionalized structures are directly 3D printed on top of a commercial contact lens. Atto dyes enable red-green and blue-yellow color vision correction. Photochromic dye enables UV monitoring, warning the wearer in case of UV hazards. Multifunctional contact lenses which can perform ocular health monitoring can also be produced through these techniques. Drug delivery is explored from drug-loaded structures added on the contact lens. Herbal eye drops and phenol red were utilized for studying drug release. The dyes and drugs are incorporated into hydroxyethyl methacrylate and polyethylene glycol diacrylate (HEMA:PEGDA) hydrogels. Drug release rate can be varied by varying the drug loading or the hydrogel composition. The multifunctional contact lenses displayed excellent optical and material properties. Drug loaded structures are printed as peripheral structures that do not hinder vision. These multifunctional contact lenses can enable simultaneous color vision correction, health monitoring and drug delivery without disturbing the daily routine of the wearer. The study demonstrates the potential of vat photopolymerization 3D printing for cost-effective production of multifunctional contact lenses.