Nominal Ocular Dazzle Distance is a new concept by Craig Williamson of DSTL_Porton Down and Leon McLin of the US Air Force 711th Human Performance Wing.
Most PLers and LPFers view optical disruption of vision by the damage threshold, Nominal Ocular Hazard Distance, NOHD, and some advanced ones who have read into the matter calculate the Sensitive and Critical Zone exposure distances used in aviation laser safety for laser shows. Others just go by the basic laser classification system of class I to IV. What NODD does different is it helps estimate what the laser "Dazzle" does to visual acuity off axis to the laser strike.
The proposed concept, gives a more accurate view of what happens when performing a task while a portion of the eye is laser illuminated, and while the fluid in the eye and surface of the retina is scattering laser light. This scattered light can greatly affect visual acuity elsewhere in the eye.
NODD is also dependent on the angle of beam entry to the eye, as well as the angle to the viewing target such as a runway threshold.
The results of this calculation might surprise most of the naysayers who think even low power pointers cannot possibly interrupt a pilot's task during approach or at high altitude flight. This paper is the first published means to help determine a qualitative level of visual field disruption in a meaningful way.
Stray Light and Veiling Glare matter....
More to come.
Steve
Reference Citation:
Craig A. Williamson and Leon N. McLin, "Nominal ocular dazzle distance (NODD)," Appl. Opt. 54, 1564-1572 (2015)