Final answer:
Glasses for laser eye protection must match the specific wavelengths of the laser being used. CO₂ lasers require lenses that block 10,600 nm, whereas Nd:YAG, ruby, and potassium titanyl phosphate lasers require lenses that block 1064 nm, 694 nm, and 532 nm respectively. Polycarbonate lenses are preferred due to their higher UV protection.
Step-by-step explanation:
The types of glasses needed for laser eye injury prevention depend on the wavelength of the laser in use. For CO₂ lasers, glasses that specifically block or absorb the 10,600 nm wavelength are required. On the other hand, Nd:YAG, ruby, and potassium titanyl phosphate lasers operate at different wavelengths: 1064 nm for Nd:YAG, around 694 nm for ruby lasers, and 532 nm for frequency-doubled Nd:YAG, which is what's used in potassium titanyl phosphate lasers. Protective eyewear for these lasers must be designed to filter out those specific wavelengths. Moreover, the glasses should provide full coverage to prevent light from reaching the eyes from the sides.
It is important to note that ordinary glasses or untreated glasses do not provide sufficient protection against laser light. Polycarbonate lenses are often recommended because they provide greater protection by blocking most UV light. This is crucial because lasers produce intense, well-focused light which could easily damage the retina without proper protection. A material's ability to strongly absorb laser light, like in the case of excimer lasers used for LASIK surgery that emit 193 nm UV radiation, allows precise work and minimizes damage to surrounding eye tissues. Protective eyewear is thus a critical component of safety when working with or around lasers. Laser safety glasses must be carefully selected to match the wavelength of the laser to ensure they provide adequate protection.