I have returned to the topic of light levels and their importance to ECPs in this column with a regularity that might be described as circadian.
I recently saw a young patient who was complaining about her current specs. I was surprised to see that the specs had blue tinted lenses. She had been wearing them full time, but felt they were uncomfortable and not helping with her reading challenges.
Whether or not the tint had been selected appropriately for her reading concerns, I was surprised to hear that no one had ever mentioned the evidence that a blue tint worn by a young patient for outdoors might not be a good idea, allowing potentially maculotoxic light to reach the retina.
I was more surprised to find a decompensated near phoria and long near point of convergence that no one had previously thought might be a major contributor to her near discomfort. And I was somewhat surprised that no one had mentioned the tint might not be the best for evening revision due to its potential to affect sleep patterns.
Unlike some areas of vision science, there is increasing solid evidence about the potential for light to affect health. Only last weekend, Professor Robert Fosbury, of the Institute of Ophthalmology at University College London (UCL), reported: ‘When reddish light shines on our bodies, it stimulates mechanisms including those that break down high levels of sugar in the blood or boost melatonin production.
'Since the introduction of fluorescent lighting and later LEDs, that part of the spectrum has been removed from artificial light and I think it is playing a part in the waves of obesity and rises in diabetes cases we see today.’
UCL is now installing infrared lamps to help patient recovery.
Is it time to shift the focus when considering tinted lenses?