Using Light lasers:
Light lasers are used to mark, engrave and cut various materials to a very high precision, it can do this because the energy is focused to produce a small but powerful beam point. It is non-contact application where the light laser is aimed at a specific surface area to either mark, engrave or cut it, but which in turn means the light can be reflected off the material.
Although it is machines that direct the light, engineers are the ones who operate the machines and manually ensure each material or product is laser marked, engraved or cut correctly. As they are working with light and as light is reflective these laser technologies pose certain risks to them, specifically to the eyes.
How the eye, specifically the Retina, is sensitive to light:
Eye Smart explain the break down of what the retina is to help us understand how the light from the laser would effect it.
- The retina is the light-sensitive tissue lining at the back of our eye.
- Light rays are focused onto the retina through our cornea, pupil and lens.
- The retina converts the light rays into impulses that travel through the optic nerve to our brain, where they are interpreted as the images we see.
- A healthy, intact retina is key to clear vision.
How the light laser could effect the retina:
Light from the laser is normally manipulated to be directed one way, aka providing a collimated beam, so that it can accurately be manipulated through lenses and is therefore powerful and stronger than a natural light ray, as it is focused down into a spot of less that a micron. It reflects off the surface material and if you’re looking at the laser, because the retina has a light sensitive tissue lining, your eye will refocus the wave length.
As the light wave length has been created to be strong enough to mark, engrave and cut metals and plastics this intense light that is refocused, when looked at by the naked eye, will cause damage.
The different wave lengths refocus the light differently, changing the damage.
- Fibre ND:Yag – damages the back of your eye.
- Co2 – damages the front of the eye.
How to prevent this danger:
Although this is a high risk type of damage it can be easily avoided with the use of green safety glasses.
Why are they coloured green?
- Green is the colour of the relevant wavelength blocker.
What is the protective screen on them?
- The lens material is coated or layered with a film that prevents the penetration of the laser wavelength. In the case of green this is for Nd:YAG wavelength which sits at 1064 nm.
How do the green safety glasses actually work?
- The screen protector on the glasses blocks the light reflecting off the material from refocusing onto your retina, ensuring your eyes remain undamaged and the engineers can safety check the laser is marking, engraving and cutting to a high standard.