The difference a high-index lens material can make: the same correction for nearsightedness in regular plastic lenses left vs.
With over twenty different features, Iris is a worthwhile expense to protect your eyesight. Blue light filter glasses have become increasingly popular due to the recent studies revealing the potential damage and health concerns surrounding blue light. The latter combines the comfort of hydrogels with the oxygen-permeability of silicone, enabling the user to wear the lenses for longer stretches of time. The second was how to achieve the optimum concentration of molecules to deliver the visual benefit, while still looking good on the eye. Question That Original Mix. Kim explained.
Images: Essilor. Refractive errors and lens powers required to correct them are measured in units called dioptres D. If you are mildly shortsighted, your lens prescription might say If you are highly myopic, it might say Regular glass or plastic lenses for high amounts of shortsightedness or long sightedness can be quite thick and heavy. Fortunately, manufacturers have created a variety of new "high-index" plastic lens materials that bend light more efficiently.
This means less material can be used in high-index lenses to correct the same amount of refractive error, which makes high-index plastic lenses both thinner and lighter than conventional glass or plastic lenses. Because of their ability to bend light more efficiently, high-index lenses for shortsightedness have thinner edges than lenses with the same prescription power that are made of conventional plastic material. Thinner edges require less lens material, which reduces the overall weight of the lenses.
Lenses made of high-index plastic are lighter than the same lenses made in conventional plastic, so they're more comfortable to wear.
High-index glass lenses also have thinner edges, but high-index glass is heavier than conventional glass, so there is not as much weight savings with glass as there is with plastic lenses. And most high-index lenses also have an aspheric design , which gives them a slimmer, more attractive profile and reduces the magnified look that conventional lenses cause in strong longsighted prescriptions. There is a wide variety of thin, lightweight high-index spectacle lenses, based on how efficiently they bend light.
The light-bending ability of spectacle lenses is determined by the "refractive index" of the lens material. This refractive index is the ratio of the speed of light when it travels through air to the speed of light when it passes through the lens material. The speed of light is reduced the more it is refracted as it passes through a lens material. Therefore, lenses that bend light more efficiently have a higher refractive index than those that bend light less efficiently, and lenses with a higher refractive index are thinner than lenses of the same power made of materials of a lower refractive index.
Conventional plastic lenses have a refractive index of approximately 1.
For glass, it's 1. If you have trouble waking up in the morning or focusing, a source of blue light can assist with both. But is blue light harmful to the eye?
Because the wavelength of blue light is short and powerful, it can penetrate past the cornea to reach the retina, which is the most light-sensitive part of your eye. One of the most common side effects of blue light exposure is digital eye strain. If you stare at a computer screen for too long, you may start to experience pain in your eyes and headaches.
Digital eye strain, also known as computer vision syndrome, may lead to dry, sore, red eyes and blurred vision. With enough prolonged exposure, blue light can harm your eyes and lead to macular degeneration - causing damage the same way UV rays would. However, avoiding permanent damage to your eyesight is fairly easy because it takes a significant amount of prolonged, repetitive exposure. A study performed by Harvard Medical School found that blue light suppresses melatonin for about twice as long as green light and shifts circadian rhythms by twice as much .
The same study also found that green light may be damaging and strenuous on the eyes as well. The typical wavelength of blue light falls between and nanometers. The wavelength for green light is to nanometers, with cyan falling in between. Of course, this is much easier said than done given how much we all depend on our devices and computers. As we age, the lens inside our eye can lose flexibility, resulting in the inability to change focus from far to near.
Getting regular comprehensive eye exams are an important component to maintaining eye health, no matter how much time you spend in front of screens. If you already have prescription glasses, you can move to multi-focal lenses. You can also have your optometrist add a blue light filter on your glasses or find reading glasses that include one.
Dry eyes are irritated eyes. This lubricates and cleans our eyes, and in normal situations the average person blinks 10 to 20 times per minute. Unfortunately, studies have shown that when we concentrate, our blink rate drops. We only blink 3 to 8 times per minute when reading, watching TV, or looking at a computer screen . Take time to rest your eyes every 20 minutes or so.
Look away from the computer and focus on something distant - like a poster on the wall across the room or out a window.
Close your eyes gently, then squeeze and hold them shut for a moment, then open and relax them. Try to remember to blink more often in between, too, and when you are thinking, instead of squinting at the screen, turn away and blink a few times.
Your eyes will thank you. A blue light filter can either be a physical barrier that repels and blocks out blue light or an application that changes the light emitted by your device or computer display. However, they are effective at reducing your exposure and protecting your eyesight.
One of the most popular blue light filter applications is F. Like most blue light filter applications, F.
One of the unique features that makes F. Rather than setting timers and remembering to activate the filter on your PC or device, F. Iris is one of the most intuitive and user-friendly blue light filter applications.
With Iris , you can choose from a variety of modes and types within the settings menu. Select from options like automatic, manual, and paused mode for your convenience and preference. Within the type settings, you can select health, reading, programming, biohacker, sunglasses, dark, movie, and overlay. Each of these options gives the user a slightly different experience and changes the display setting to accommodate specific tasks or activities. Video and movie displays are often the most affected and distorted by application-based blue light filters. Fortunately, the video setting on this blue light filter is one of the best.
With over twenty different features, Iris is a worthwhile expense to protect your eyesight. Physical blue light filters work by blocking short, high-frequency waves and allowing long, low-frequency waves through. If you were to do a side-by-side comparison of blue light filter applications and physical blue light blockers like glasses, it would quickly become apparent that the physical barrier diminishes the quality of the picture and color far less than its application-based counterpart.
Filtering screen covers. Physical blue light filters are the easiest and best way to reduce your blue light exposure. Some blue light filters for PCs are just a clear piece of plastic material that covers your monitor, while other filters come in the form of blue light blocking glasses. Blue light filtering glasses.