Effect of blue-blocking lenses on colour discrimination

A review of the current state of research on artificial blue light safety as it applies to digital devices

Light is necessary for human health and well-being. As we spend more time indoors, we are being increasingly exposed to artificial light. The development of artificial lighting has allowed us to control the brightness, colour, and timing of our light exposure. Yet, the widespread use of artificial light has raised concerns about the impact of altering our light environment on our health. The widespread adoption of personal digital devices over the past decade has exposed us to yet another source of artificial light. We spend a significant amount of time using digital devices with light-emitting screens, including smartphones and tablets, at close range. The light emitted from these devices, while appearing white, has an emission spectrum with a peak in the blue range. Blue light is often characterised as hazardous as its photon energy is higher than that of other wavelengths of visible light. Under certain conditions, visible blue light can cause harm to the retina and other ocular structures. Blue light can also influence the circadian rhythm and processes mediated by melanopsin-expressing intrinsically photosensitive retinal ganglion cells. While the blue component of sunlight is necessary for various physiological processes, whether the low-illuminance artificial blue light emitted from digital devices presents a risk to our health remains an ongoing area of debate. As technological advancements continue, it is relevant to understand how new devices may influence our well-being. This review examines the existing research on artificial blue light safety and the eye, visual performance, and circadian functions.

Long-term effects of blue-blocking spectacle lenses on color perception

The use of blue-blocking filters is increasing in spectacle lens users. Despite the low absorption in the blue range, some users complain about these filters because they affect their color perception. In a pilot study we have evaluated how the long-term use of 8 different blue-blocking filters impact the color perception during more than 2 weeks on a group of 18 normal color vision observers, compared with a control group of 10 observers. The evaluation was done using the FM100, the Color Assessment and Diagnosis (CAD) and an achromatic point measurement. Our results show that there is a trend to worsen with the filters on.