You may have seen them in action in a movie, or on one of the popular crime scene investigation television shows. The crime scene is locked down, the area cleared, and in comes a forensic scientist or investigator. The lights go down. A specialty lamp, dark blue or purplish, is switched on to illuminate the scene. The investigator, wearing a pair of brightly-colored glasses or goggles, looks about and notices a missed fingerprint or a hidden blood stain…important evidence that was missed under normal lighting conditions. Case closed.
About Forensic Glasses
Those unique glasses are forensic glasses. Utilizing distinctly-colored lenses and in conjunction with an ultraviolet lamp, they reveal traces of florescence, tell-tale signs of bodily fluids and oils. Forensic glasses are a key tool for forensic examiners, medical technicians, and police investigators.
How do they work? Substances emit visible light when exposed to X-rays or UV light. Different substances react at different wavelengths. So certain substances that are invisible under “normal” light will jump out when exposed under a UV lamp…if you have the right color lens for the right substance.
Three lenses are used:
- Red Lens, which transmits 2% at 583nm.
- Orange Lens, which transmits 2% at 549nm.
- Yellow Lens, which transmits 2% at 480nm.
Forensic glasses filter out reflected light from all but the selected wavelength, revealing whatever substance the investigator is searching for. Once identified, samples can be taken for further investigation, and cameras fitted with the appropriate red, orange, or yellow filter can photograph the scene. Forensic glasses and UV lamps can be found in any forensic investigator’s toolbox.
Phillips forensic glasses are available in nine different styles. Some utilize a wrap-around format while others are designed to fit over prescription eyewear. Features on the various styles include splash and side protection, adjustable and telescoping temple bars, ANSI Z87 safety ratings, chemical-resistant lightweight nylon frames, rubber nose pads, and rubberized temple bars. All nine styles are available with any of the three lens colors described above, offering Phillips Safety customers a total of 27 different choices.