The natural breeding season occurs during the spring and summer months where there are extended periods of daylight.  Artificial lighting has been used throughout the horse industry to advance the mare breeding season by increasing the horses duration of light exposure each day.  This additional exposure to light inhibits the hormone melatonin and triggers the equine reproductive system to activate earlier in the year.

Equilume Light Masks utilize short wavelength blue light, ​a major component of natural light, to mimic the effects of daylight on a horse.  Masks are secured with velcro straps on open mares around November 15th for a period of 90 days or on pregnant mares approximately 60 - 75 days prior to their due date.   The horse wears the mask throughout the day and the light automatically activates based on a specific schedule and the amount of ambient light (depending on the model of the mask).  The light then remains on until 11 PM each day and automatically turns off.  This cycle repeats each day and eliminates the need for any additional artificial lighting, horses can be turned out in the pasture during the winter months and still receive the benefits of the timed blue light.​