Insomnia was not observed to be a side effect of blue-light filtering IOLs in this study. Photo: Isabella and Zsa Fischer on Unsplash.

Protecting the retina from phototoxicity by choosing an IOL that filters out visible blue light, while not mainstream practice, does have its proponents. However, these implants are controversial in some cases; blue-blocking lenses have the potential to interfere with the circadian rhythms essential to healthy sleep. However, few long-term studies have been done to document their effects on sleep patterns. In a recent study, researchers compared the incidence of clinically diagnosed insomnia after cataract surgery over a 10-year period in those with blue light-filtering IOLs and those without.

The study enrolled approximately 170,000 patients who underwent cataract surgery in both eyes between 2008 and 2013 and followed them until 2018. Of the sample, 11.4% had blue-blocking IOLs and 88.6% opted for standard ones. It’s worth mentioning that the former group was younger and had fewer chronic diseases. Additionally, patients who were diagnosed with insomnia three years prior to cataract surgery were excluded.

No significant difference in the incidence rate of insomnia was found between the two IOL groups when treating all-cause mortality as a competing risk. This was consistent with a previous study showing that blue light-filtering IOLs did not have a detrimental effect on sleep quality within seven to 12 months after IOL implantation.

Subgroup analysis revealed no significance in the insomnia rate between the two IOL groups based on age, sex and presence or absence of benign prostatic hyperplasia.

A previous study showed that conventional IOLs are associated with a lower risk of long-term death than blue-blockers. The authors of this study, however, observed lower mortality in the blue light–filtering IOL group.

In conclusion, the authors note, these results support the contention that blue light-filtering IOLs have no detrimental effect in causing insomnia after cataract surgery.