JULY 2023 | EYEWORLD | 53
R
Dr. Waring emphasized that the benefit of
violet filtration for low light contrast sensitivity
is typically the most challenging visual envi-
ronment, in particular with diffractive presby-
opia-correcting IOLs. The violet filtration helps
by reducing light scatter and improving image
quality, improving low light contrast, improving
low light reading performance, and mitigating
and reducing dysphotopsias, he said.
In terms of patients for whom high ener-
gy light filtering would be most beneficial, Dr.
Chang said that while there are many potential
benefits, demonstrating them clinically can be
challenging. "Traditional clinical vision tests are
simply not designed to study the visual impact
of high energy light filters, much less differenti-
ate them." As an example, the emission spectra
of lighting or glare sources used in vision tests
are not routinely characterized. Warmer vs.
cooler lights, fluorescent vs. LED lights, white
vs. monochromatic light may all impact testing
results, particularly when considering the effect
of a chromophore, yet few studies even consider
these factors. There have been some popula-
tion-based epidemiological studies, but it's hard
to isolate the impact of the chromophore alone.
"Part of the problem is blue light-filtering has
become a marketing concept," he said. "The
challenge is to address the topic with enough
specificity for relevance without so much com-
plexity that people are unable to follow."
Dr. Chang said he would be interested to
learn more on this topic through further studies.
Fundamentally, clinical testing of vision is quite
limited, he said. Our vision tests were not cre-
ated to understand visual quality in real-world
contrast and lighting conditions, which are key
to understanding IOL performance. For now, he
said it's important to increase awareness that
high energy light filtering is about more than
just macular protection and more than just
marketing hype.
