Blocking the blue
- Correspondence to: Patricia Hawse The Wilmer Eye Institute, Johns Hopkins University, 2501 Edison Highway, Baltimore, MD 21213, USA; phawse{at}jhmi.edu
The role of blue light exposure from ophthalmic diagnostic equipment deserves further study
Recent research surrounding the development of a blue blocking intraocular lens (IOL) for cataract surgery has again raised the question of the potentially harmful effects of light on the retina, particularly the blue light hazard. Does the literature support the hypothesis that blue light exposure contributes to the development of retinal damage, particularly macular degeneration? And, if we are developing blue blocking IOLs to reduce this risk, should regulators consider mandating the use of blue blocking filters in diagnostic equipment (slit lamps, direct and indirect ophthalmoscopes, ophthalmic cameras, and magnifying lenses) as well?
The controversy over the immediate visual benefits of blue blocking IOLs is still under debate. Recent research has found that contrast sensitivity and colour vision improved with blue blocking IOLs in diabetics,1 while earlier research found that blue blocking IOLs reduce scotopic sensitivity in ageing individuals.2 None the less, regardless of whether or not blue blocking IOLs make sense for different types of cataract surgery patients, the research regarding the detrimental effects of blue light on the retina still remains.
Research on rhesus monkeys, conducted decades ago, found that exposing the retina to the light of ophthalmoscopes produces retinal lesions and damages the retinal pigment epithelium after 15 minutes.3 More recent research on the indirect ophthalmoscope supports these early findings. Using spectral radiometric measurements from …
