The Influence of Intraocular Lenses (IOLs) on the Properties of Filters Protecting Human Eyes against Optical Radiation in the Work Environment

Abstract

Under the specific illumination conditions of many workplaces, e.g., in the metallurgical industry, decreased lighting may impair workers’ vision and, as a result, their productivity. Spectrophotometric tests of two types of protective optical filters (welding filters and infrared protection filters), two types of intraocular lenses (IOLs with and without yellow chromophore), and filter-IOL systems were carried out. In spectrophotometric studies, the spectral characteristics of transmission and the coefficients for the assessment of light transmission were determined. This study explores the relationship between the eye protection levels offered by filters and the use of intraocular lenses (IOLs), and especially those containing a yellow chromophore which may lower the luminous transmittance of protective filters. In our previous works, we studied a large number of optical protective filters and many factors influencing their performance. A review of the literature has shown the absence of prior research on the subject. For this purpose, transmittance reduction factors were defined for the evaluation of the filter-IOL system. The spectral characteristics of luminous transmittance for the tested IOLs indicate a significant decrease of transmittance for those with yellow chromophore within the range up to approx. 475 nm, as compared to IOLs without chromophore. The main objective of this study was to determine whether people with IOLs need different protective filters against harmful optical radiation as well as whether IOLs may change the required category of protective filters. The key finding is that while the use of IOLs in conjunction with protective filters does change the light transmission coefficient, it does not affect the filter protection levels. The transmittance reduction factors were similar (0.95 to 0.99 relative units) for all filter-IOL systems irrespective of the presence or absence of yellow chromophore. It must be said clearly that, in reference to the requirements specified in the standards, IOLs did not affect the filter protection levels. This means that the quality of vision did not change significantly when using the analyzed filters and IOLs.