Helmet-Mounted Displays (HMDs) do not allow the pilot to change transmission level of a visor transitioning from high
to low light levels. A variable-transmittance visor (VTV) is a possible solution. The Eclipse Variable Electrochromic
Device (EclipseECD<sup>TM</sup>) is well suited for these light modulation applications. The EclipseEC<sup>TM</sup> modulates light
intensity by changing the transmission level under an applied electric field. The optical density may be continuously
changed by varying voltage. EclipseECD<sup>TM</sup> is comprised of vacuum deposited layers of a transparent bottom electrode,
an active element, and a transparent top electrode, incorporating an all, solid-state electrolyte. The solid-state electrolyte
eliminates possible complications associated with gel-based technologies, the need for lamination, and any additional
visor modifications. The low-temperature deposition process enables direct application onto HMD flight visors.
Additionally, the coating is easily manufactured; can be trimmed, has near spectral neutrality and fails in the clear
(bleached) condition. Before introducing VTV technology to the warfighter, there are numerous human factors issues
that must be assessed. Considerations include optical characteristics such as transmissive range, haze, irising, internal
reflections, multiple imaging, user controllability, ease of fit, and field of view. Advanced materials tailoring coupled
with meeting critical criteria will help ensure successful integration of VTV technology.