As you mention, there are IOLs that filter blue light. My understanding is approximately 50% of the 3.1 million IOLs implanted each year are blue-blocking (usually providing the amount of blue filtering consistent with a 30-40 year old crystalline lens).
The best "smoking gun" I've seen was a study featured in the
Journal of Cataract & Refractive Surgery titled
"Prevention of increased abnormal fundus autofluoresence with blue light-filtering intraocular lenses" (you can find the study here
http://www.sciencedirect.com/science...86335015010330).
The study included 131 eyes fit with IOLs (52 with blue-filtering IOLs and 79 with clear IOLs). Two years after surgery,
none of the eyes fit with blue-filtering IOLs showed abnormal fundus autofluorescence- however, development or increase of autofluorescence was found in
12 of the eyes fit with clear IOLs. Also, the incidence of AMD was statistically significantly higher in the clear IOL group (p=0.042).
Yes, the study could have been larger (I would hope there are researchers following up as I type)- but this is the kind of data that leads me to conclude that yes, blue light is a real problem- especially for eyes that are no longer "protected" by a yellowing natural crystalline lens. Once you accept that blue light is likely a contributing factor to AMD, the question becomes "How much exposure is enough to trigger a negative impact (and as an optician, what should I be doing for my patients)?"
For sure, patients should be encouraged to protect themselves from sunlight (which they should be doing anyway, to prevent UV damage). In some ways, blue light from the sun is worse than UV (after all, a crystalline lens can be replaced- but a retina cannot). If I'm not encouraging patients to wear a hat and either sunglasses or photochromic lenses when they go outside, I'm just not doing my job (good lord, it only takes a moment to make such a recommendation). Personally, after reading study after study on blue light I find myself religiously wearing my sunglasses when I'm outside (plus, light really bothers me anyway).
Indoors? Admitting to possible bias, I think I would be pretty comfortable recommending lenses with the
Smart Blue Filter feature (yes, these lenses are made by Essilor). The lenses are basically clear, there's no extra charge for it (found in Eyezen+ and digital Varilux progressive lenses), and they reduce exposure to blue-violet light which has no known beneficial effect and may be a contributing factor to retinal disease.
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