Eyes are sensitive to the visible light spectrum. Blue light has the shortest
wavelengths and the most energy in the visible light spectrum. Blue light is
defined as visible light ranging from 380 to 500 nanometers (nm). The entire
visible spectrum rages from 380nm to 700nm. This means that blue light makes up
1/3 of all visible light. The main source of blue light is sunlight, however
man-made light also emits blue light. Blue light is emitted from LED lighting,
fluorescent lighting, TVs, phones, tablets and computers. The light might
appear white to us, but it is emitted in the range of 400-490nm, which is
technically blue light.
Macular Degeneration is the leading cause of vision loss, affecting more than 10 million Americans – more than cataracts and glaucoma combined. At present, Macular Degeneration is considered an incurable eye disease.
Over exposure to blue light can damage the light sensitive cells in the retina, which resembles the changes of macular degeneration. Macular Degeneration is caused by the deterioration of the middle portion of the retina, the inside back layer of the eye that records the images we see and sends them via the optic nerve from the eye to the brain. The retina’s middle portion, known as the macula, is responsible for focusing central vision in the eye, and it controls our ability to read, drive a car, recognize faces or colors, and see objects in fine detail. Macular Degeneration can lead to slightly blurred central vision that cannot be corrected with glasses. Other symptoms include: the sense of dirt in the eye, increased blurred area, wavy or distorted vision, and dark spots blocking out portions of the central vision.
One can compare the human eye to a camera. The macula is the
central and most sensitive area. When it is working properly, the macula
collects highly detailed images at the center of the field of vision and sends
them up the optic nerve to the brain, which interprets them as sight.
When the cells of the macula deteriorate, images are not received correctly.
In initial stages, macular degeneration does not affect vision. Later, if the
disease progresses, people experience wavy or blurred vision, and, if the
condition continues to worsen, central vision may be completely lost. People
with very advanced macular degeneration are considered legally blind. Even so,
because the rest of the retina is still working, they retain their peripheral
vision, which is not as clear as central vision.
There has been a steep increase in the amount of time that children spend in front of digital screens. Individuals of all ages are spending a large amount of time staring at digital screens. The CDC reports that children now spend nearly 9 hours a day on digital devices. The screen time is raising concerns and suggestion for further research have been raised.