Well, it is undoubtedly true that any bright light is potentially harmful when it is straight projected into your eyes. However, until and unless you directly look into the source of light of the laser projector, you have absolutely zero possibilities of harm. The visible light, reflected from a screen on which a laser projector is displayed, possesses no hazard.
Do Laser Projectors Damage Our Eyes?
Staring straight into the projection lens of a laser projector can be significantly damaging; in certain cases, it may also result in permanent eye damage.
Before we get any further, let us dive into the simplicity of a how a few beams from a laser pointer and crystals work together to release this waltzing array of organized photons of light that manifest into images for your presentation at the office and also animations for your quality time at a relaxed weekend with your beloved family.
Do you know how laser projectors work?
LASER, i.e. light amplification by stimulated emission of radiation, is used in multiple devices such as barcode scanners, fiber optical wires, and projectors.
In projectors, primary-colored lasers which are red, blue, and green, shoot light from a laser pointer through a rotating mirror and then are passed through the lens.
The lens in turn magnifies and focuses the laser beam through a color wheel to produce a desired image or animation through the final projection lens.
Effects of Laser light on eyes and are they harmful?
The human body and all of its organs are a carefully constructed equilibrium that has heavily restricted constraints. This means too much of anything can be detrimental to us. The eyes, that are so exposed to the world, even more so.
This is why the production of Laser Projectors kept in the mind the fragility of the human eyes, and the functionality to minimize injuries like retinal damage and prioritize eye health, before releasing their products to consumers.
A maximum of 5 mW at a high enough intensity can have the means to cause retinal damage. So, laser projectors use light below 5mW at very low power. The low laser power inhibits the presence of a high intensity making the projector light and can be tagged as harmless to eye health
Although, prolonged screen time and exposure for an extended period of time to projector light on a screen can cause eye damage.
So extended use of laser projectors should be avoided in order to not strain the eyes.
But this is not the only way a projector light may have the ability to cause eye injury.
When used on a screen, the intensity of the projection’s indirect light is not strong enough to cause any damage but when purposefully peered directly at, the intensity can be dangerous and eye damage is an inevitable outcome.
How do laser projectors damage eyes?
Before we discover how eyes can be harmed by light from a projector lens, we need to develop an idea of how the built-in projectors in our skull, our eyes, work to produce an image in our head to understand what exactly goes wrong that compromises our vision.
Direct exposure to light from the projection lens can irritate the eyes to a certain degree. This includes pain in the eyes and redness. But is the damage limited to temporary uneasiness and discomfort? I’m afraid not.
The furthest extent of damage light-sources from a projector lens is disfiguring the retina or the destruction of rods and cone cells. This makes light detection poor leading to impaired vision. In some extreme cases, if the injury is left untreated, it can lead to vision loss.
How to protect your eyes from laser projectors
As discussed earlier, to avoid strain on the eyes, avoid using a projector for long periods.
Under no circumstances, are we to look directly into a projector lens. A laser projector is only harmful if we stare directly into the projector lens.
If long-term exposure cannot be avoided, it is recommended to use a bluelight-blocking glass that reduces the reach of blue light to the eyes. This decreases strain by a significant amount.
Moreover, blue light blocking glass has alternatives like night mode or reading-mode integrated into devices that generally increases the wavelength of light to maximize optical safety.
Nevertheless, the light emitted from a laser projector is mostly visible light, and a certain glance or an accidental exposure is less likely to result in an injury. The final and only instruction you should strictly follow is not to stare directly into the light source of any projector unless you want serious eye damage.