A research group in China has developed a “smart” contact lens that can show real-time changes in moisture and pressure by changing colors. The lens can potentially be used for point-of-care diagnosis of xerophthalmia and high intraocular pressure disease, according to a press release.
Early diagnosis is important for avoiding severe eye problems such as exophthalmia, which causes relatively mild symptoms, and glaucoma, which may lead to loss of vision. Such diagnoses depend on “facile and reliable monitoring of several features with significant pathologic relevance, such as the amount of tears and intraocular pressure,” notes the release from the Chinese Academy of Sciences.
However, current methods “usually require complex procedures and instruments operated by professionals, causing difficulties for point-of-care ophthalmic health monitoring.”
The “smart” contact lens “features periodic nanostructures within the poly(2-hydroxyethyl methacrylate) (pHEMA) hydrogel matrix, resulting in bright, tunable structural colors ranging from red to green to blue,” according to the release.
This structurally colored contact lens sensor is made solely from a biocompatible hydrogel, without the addition of any chemical pigments, “thus exhibiting superior biosafety and comfort for wearable applications.”
“Importantly, the spacing of periodic nanostructures within the pHEMA hydrogel are sensitive to changes in moisture and pressure, leading to real-time color changes in the ‘smart’ contact lens,” according to the release.
Advertisement
“Based on these features, the ‘smart’ contact lens was explored as a means for monitoring xerophthalmia and high intraocular pressure disease. In normal eye-simulation conditions, its color will not change over time; while its color changes from red to blue in the xerophthalmia-simulation condition in about 25 minutes,” said Zhao Qilong, first author of the study.
The work was led by Professor Du Xuemin from the Shenzhen Institutes of Advanced Technology of the Chinese Academy of Sciences.
“This study provides a novel and smart wearable device for timely and facile warning of the risks of xerophthalmia and high intraocular pressure disease. It will also inspire the design of a new generation of wearable devices with colorimetric sensing capabilities for real-time POC monitoring of various human body signs and diseases,” said Du.
The results were published in Journal of Materials Chemistry B.
