The most common effects of too much blue light exposure are eye strain, blurred vision, and headaches. However, recent studies have focused on blue light’s negative impact on the circadian rhythm and found that watching TV or using a tablet before bedtime, for example, can result in restlessness and disrupted sleep cycles. In extreme cases, too much blue light exposure can even lead to permanent eye damage and vision loss.
Children are especially vulnerable because their eyes have not yet developed natural defenses against UV and HEV blue light. Today, a staggering 97 percent of American kids under the age of four use mobile devices, and teens are spending an average of 6.5 hours per day on screens. Now that kids are using more digital devices at home and school starting at a young age, it’s important to protect their eyes as much as possible.
The molecules responsible for causing photochromic lenses to darken are activated by the sun's ultraviolet radiation. Because UV rays penetrate clouds, photochromic lenses will darken on overcast days as well as sunny days.
Photochromic lenses typically will not darken inside a vehicle because the windshield glass blocks most UV rays. Recent advancements in technology allow some photochromic lenses to activate with both UV and visible light, providing some darkening behind the windshield.
-------Progressive lenses are line-free multifocals that have a seamless progression of added magnifying power for intermediate and near vision.
-------Instead of having just two or three lens powers like bifocals or trifocals, progressive lenses are true "multifocal" lenses that provide a seamless progression of many lens powers for all viewing distances.
------With progressive lenses, you can look up to see clearly across the room and in the distance. You also can look ahead to view your computer in the intermediate zone and drop your gaze downward to read and do fine work comfortably through the near zone of the lenses.
------And it's easy to adapt to today's modern progressive lenses.