National Eye Care Day | Do You Know Speckle Damage to Eyes?
As China celebrates its 23rd National Eye Care Day, we wonder whether you care the eyes when you are obsessed with phones, computers and other health hazards that take over your work and life. By contrast, a giant screen seen from far away seems harmless. What most people do not realize is that our two "windows" to the soul are becoming unwitting victims during 90 minutes in the cinema.
Eye Care in Cinema - Tip 1:
Appropriate screen brightness is essential to eye health.
This is always the case: 3D glasses will make gloomy screens even worse, leaving many details indiscernible. As a result, we have to widen our eyes to see things, which means that the pupils will dilate for a long time. In other words, watching a film in such a way will put a lot of pressure on our eyes. How to solve the problem? A laser room provides the answer to a great extent.
The biggest advantage of laser projection is high brightness which can hit nearly 60,000 lumens. A laser light source projector can largely increase screen brightness and allow the audience to see fancy and vivid images even with 3D glasses. While traditional xenon lamp projection can reproduce 53.65 % of natural colors visible to human eyes, laser projection can reproduce around 74.6%, presenting perfect images most pleasant to our eyes.
Eye Care in Cinema - Tip 2:
Say No to Speckles
With sufficient brightness, can we stop worrying about our eyes? Not necessarily. To some laser projection technologies, speckles remain intractable. "When a rough surface is illuminated by a coherent laser source, randomly distributed speckles, including bright and dark ones, are formed due to the scattering of light rays on the rough surface."
How do laser speckles damage human eyes? Let's take a look at the eye structure first.
After passing through the cornea, anterior chamber filled with aqueous humor, and pupil in a row, the light is refracted via the lens and vitreous body which project a clear image onto the retina. The image stimulates photoreceptor cells in the retina to generate nerve impulses that are sent through the optic nerve to the visual center of the cerebral cortex where the image is perceived. The dioptric system of human eyes can focus on visible and near-infrared lasers, which feature an irradiance power density on the retina 105 times higher than that on the cornea. In other words, the luminance of speckle received by the retina is 105 times the average luminance of the rest parts (cornea or skin). When the speckle luminance exceeds a certain limit, it may harm the retina. Statistics show that the speckle reflected by the projection screen may have 5% and 0.01% chances to be three times and nine times the average luminous intensity respectively. In this light, the damage of laser speckles to human eyes has multiplied.
Native speckle-free laser imaging is therefore important for laser light cinemas, and ALPD® provides a perfect solution. The mix of laser and phosphor, on one hand, satisfies luminance required for 3D imaging, and on the other hand, prevents the generation of speckles and any potential harm to the audience's eyes. On the National Eye Care Day, we hope that you can take better care of your eyes while enjoying a movie. We suggest that you select speckle-free laser imaging cinemas. There are by far more than 9,000 CINEAPPO laser rooms with ALPD® projectors in China. Please follow our WeChat official account. You can find the CINEAPPO laser room nearest to you via the "Interaction" button in the bottom menu. Wish you a pleasing, worry-free experience watching films in the future!