Bright burning laser pointer color contrast

With so many different laser pointers to choose from today, understanding the science behind the brightest colors and highest power output is not so simple. It is important to know what makes one laser beam brighter than another at the same mW power, and what makes it a true thermal laser. Class II and IIIa laser pointers are considered safe because the reflection response time of the eyes is about 0.25 seconds. At <5 mW, the energy density of the laser beam (W/cm2 or J/cm2) is not enough to cause biological damage and protect the eyes. Once the 5mW limit is exceeded, the blink reflex no longer provides protection.