Contact lense research today
More than 100 years after the publication of Adolf Fick's doctoral thesis ‘Eine Contactbrille’ in 18881, the topic of contact lenses is still the subject of numerous publications on scientific journals. In this context, the reader can find the enormous amount of 371 publications about contact lenses on the medical database “PubMed” for the period from January 2024 to September 23, 2024 by entering the search term “Contact Lens Research”.
These publications include an interesting paper by Walther et al. on the topic of “On-eye centration of soft contact lenses”.2 The published study involved 101 healthy eye contact lens wearers aged between 18 and 68 years who wore the contact lenses for one hour before the fit of the contact lenses was assessed and measurements were taken. The boundaries of the contact lenses as well as the pupils and the cornea (limbus) were determined using custom validated image analysis. The analysis showed, among other things, that modern soft contact lenses were generally well centered on the cornea and limbus but significantly (p < 0.001) decentered relative to the pupil center [both temporal -0.23 mm (-0.26, -0.20) and inferior -0.08 mm (-0.12, -0.04)]. Another interesting paper ‘Frequency-encoded eye tracking smart contact lens for human-machine interaction’ was also published this year by Zhu et al.3 In their paper, the authors described a biocompatible contact lens for controlling eye movements. By using frequency coding, the chip- and battery-free lens can successfully recognize eye movements as well as eye closure. Using a time-sequential eye-tracking algorithm, the lens offers a high angular accuracy of < 0.5°, which is even less than the visual range of the central fovea.
In addition to analyzing eye movements, smart contact lenses have also been increasingly discussed for use in various areas of health monitoring for some time. These include measuring intraocular pressure and monitoring glucose levels in diabetes patients. In this context, Shi et al. discussed the use of a smart contact lens for measuring the ascorbic acid (AA) content in tear fluid in their 2024 paper ‘Contact lens sensor for ocular inflammation monitoring.4 Based on the fact that the AA content in tears is closely associated with ocular inflammation, a reusable fluorescent contact lens sensor was used to measure the amount of AA in the tear fluid. The fluorescent sensor required to determine the AA content was encapsulated in a TRIS [tris(hydroxymethyl) aminomethane] buffer in a microfluidic contact lens. In order to achieve point-of-care detection, the fluorescence signals were converted to grey scale values. A smartphone app was developed to analyze the fluorescence signals.
All three publications demonstrate the scope of current contact lens research and the associated need for further education and training for the clinicians and scientists involved.
Source:
[1] Fick, A. E. (1888). Eine Contactbrille. Archiv für Augenheilkunde 18, 3, 279-289.
[2] Walther, G., Meyer, D., Richards, J., Rickert, M., Kollbaum, P. (2024). On-eye centration of soft contact lenses. Ophthalmic Physiol. Opt., 44, 737-745.
[3] Zhu, H., Yang, H., Xu, S., Ma, Y., Zhu, S., Mao, Z., Chen, W., Hu, Z., Pan, R., Xu, Y., Xiong, Y., Chen, Y., Lu, Y., Ning, X., Jiang, D., Yuan, S., Xu, F. (2024). Frequency- encoded eye tracking smart contact lens for human-machine interaction. Nat. Commun., 15, 3588.
[4] Shi, Y., Wang, L., Hu, Y., Zhang, Y., Le, W., Liu, G., Tomaschek, M., Jiang, N., Yetisen, A. K. (2024). Contact lens sensor for ocular inflammation monitoring. Biosens. Bioelectron., 249, 116003.