Light is emitted as wavelengths, and the longer the wavelength, the less amount of energy it carries. As humans, we have a particular range of the light spectrum that we can see as light and color between approximately 380nm and 700nm, while below 380nm is ultraviolet light (UV) and above 700nm is infrared (IR).
Blue light can be harmful to your eyes, which is a fact that many of us do not realize or understand why we should care. Dr. Michael Lange goes above and beyond primary eye care, bringing a new vigilance to the way eye care and healthcare is addressed. As he implements his vision of how to provide treatment to patients, he champions avant-garde for the preservation of health for all humanity. Dr. Lange took the time to explain blue light, and how we can defend our eyes from harm.
Blue (often blue-violet), ranges from 380nm to 450nm, and blue-turquoise from 450nm-500nm. As with UV light and the risk of medical complications, blue light has high energy as it has the shortest wavelengths of the light that we can see. Unfortunately, Dr. Michael Lange explains that unlike UV light, blue light is unfiltered by our eyes, allowing this light to reach as far back as the retina. With an increasing number of technological advances (mobile phones, tablets, computers etc.) our exposure to blue light is ever increasing, and Dr. Michael Lange believes that this should concern patients and it is important to understand and help defend our eyes from blue light.
Blue Light Defense
Lens companies have come out with new lenses that allow patients to protect themselves from the harmful effects of blue light that work by filtering out this wavelength of light. There are many types of lenses available, but Dr. Michael Lange notes that there are four main considerations that should be made when purchasing blue light filtering lenses:
- The tint of the lens, some lenses may have a yellow tint
- Blue light filter should be a part of the actual lens and not a coating that can flake off
- What percent of blue light is being filtered
- If the lens can block out blue light from a laser
Dr. Michael Lange explains that there are several damaging effects of blue light that we must be concerned about:
As mentioned, our eyes do not have the natural ability to block out blue light, allowing it to pass as far back as our retina. Over time, this can damage the light-sensing cells of our retina in a similar fashion to macular degeneration, which can eventually lead to permanent vision loss.
Dr. Michael Lange explains that having the shortest wavelength and highest energy, blue light is not as easily focused, causing devices that emit blue light to have a reduced contrast and less focus. This results in our eyes trying to focus more, ultimately leading to eye strain. Glasses, such as those offered by Dr. Lange’s company ‘Blue Light Defense/Blue Light Shield’, help filter this light and make for a significantly more comfortable experience when using devices for a long period of time.
In recent times, it has become a well-known fact that computer and phone use before bed can make it difficult for humans to fall asleep, or even stay asleep. Dr. Michael Lange goes on to explain that this is due to the blue light emitted by these devices and also our physiological process, as blue light signals our brain to stop the release of the sleep hormone, melatonin.
Our body is used to seeing this blue light which is abundant in the morning sun, and near absent in the red light we see in the setting sun, allowing our body to undergo our natural circadian rhythms, which becomes interrupted by exogenous blue light delivery causing sleep disruption.
Dr. Michael Lange’s Final Thoughts
Although our technological use of blue light has significantly increased the amount of our exposure, blue light has always been a part of our environment, and not all its effects are harmful. As mentioned, one of the things it controls is our circadian rhythm, which helps in the sleep-wake cycle. Research has also shown that exposure to this spectrum of light helps with memory, cognition and alertness. It is also well documented that shorter, higher energy wavelengths (high-energy visible, or HEV light) helps in patients suffering from depression with seasonal pattern, previously known as seasonal affective disorder. If you are unsure of how to best protect your eyes from harmful light, it is strongly recommended that you seek assistance from an optometrist.