Ultraviolet radiation transmission of soft disposable contact lenses and ISO 18369: claims and compliance.

Clinical Relevance: This study was carried out to provide advice to eye care practitioners on those soft disposable contact lenses that comply with the Class 1 or Class 2 requirements of the international standard ISO 18369 for ultraviolet radiation protection.

Background: This study was carried out to provide advice to eye care practitioners on those soft disposable contact lenses that comply with the Class 1 or Class 2 requirements of the international standard ISO 18369 for ultraviolet radiation (UVR) protection and to validate any claims made. It is intended to be used when a patient needs or requests UVR protection. A revised ISO 18369-3 was published in 2017. There is no Australian adoption nor equivalent.

Methods: The direct spectral transmittance of three specimens of each of the twenty soft disposable contact lens types available in Australia in 2018 was measured in saline in a quartz cuvette with a dual beam spectrophotometer from 200-780 nm. Transmittance values for each material were averaged and scaled according to a single measurement of its transmittance in the visible spectrum (380-780 nm). Based on the ISO 18369-3:2017 criteria, lens materials were denoted as Class 1, Class 2 or non-UVR protectors. This classification was compared with any claim made by the manufacturer.

Results: All claims of the manufacturers for Class 1 or Class 2 were valid. There were no examples of any missed opportunity to make a claim. Some claims were so general as to be untestable. Some numerical claims appeared to hide that only a Class 2 claim could be made.

Conclusions: Claims of Class 1 or Class 2 were found to be appropriate. There were no missed opportunities to claim. UV protection claims that were not in the ISO 18369-3 format may be taken as Class 2 compliance but not Class 1 compliance. A two-class system of UV protectors and non-UV protectors may serve practitioners and their patients better.