INDIGLO was the first upgrade that was ever done the Timex Ironman watch. This can be considered to be a major upgrade done back in 1992. So, what is this INDIGLO? It is nothing but an electroluminescence dial. The purpose of this was to ensure that the user can check his readings and also refer to time when in an extreme dark environment. This technology was first made use of, in clocks by some other companies. However, Timex revolutionized the wrist watches by incorporating this technology in them.

This particular technology was found to be useful for midnight runners, security guards, as well as movie goers. The illumination that it produces is comparable to the full moon glow. All that the user needs to do to activate it is to press the button. The plus point of this feature was that it was carefully designed to ensure that very little battery was consumed so that the watch does not stop working right in the middle of the night.

The working principle of this INDIGLO is based on the conversion of electrical energy into light directly and not electricity to heat and heat to any incandescent bulb. Thus, the power consumption is fairly low compared to the incandescent bulb technology that most of the other manufacturers used earlier.

The illumination lasts comfortably for three seconds every time that the button is pressed, thus enabling the user to make note of the time of the day or other details such as heart rate, calories burnt, etc. For runners who reside in dark winter countries, this is the best alternative and far effective watch compared to any ordinary wrist watch. This technology was then induced into other variants of Timex running watches thus making them ultimate choice for serious runners.

Apart from the vital facilities that it provides to the athletes, fitness enthusiasts, spelunkers, security guards, and so on, they also help in entertaining movie-goers. The fun fact is that the young generation has come up with a new language using INDIGLO. Three flashes represent thumbs down while four means that it is the turn of that person to go and buy the popcorn.

The INDIGLO technology used in Timex Ironman watch has received acceptance from several athletes and people who look for some cool features on their wrist watches. Though it was the first major upgrade done to Ironman series, it still has not lost its charm and continues to exist in the recent years as well.