Seiko 7A38 - by the numbers

An observation really.

I don't normally wear my Seiko overnight but last night I woke in the middle of the night, and it was impossible to tell the time, the watch face was totally black.

I can just remember when my Seiko was new and everyday wear, it was lit up nice and clear even it total blackness.

I guess it must be due to the half-life of the illuminous paint that was used, and it has simply run its course.

Shame really.

Not that it particulary worries me, Michael. Nor is it a great surprise. The half life for Tritium (as used on most* 7Axx's) is 12.5 years - and all of these watches are over 25 years old now - most coming up to 30. Just try googling Life of Tritium lume and you'll find umpteen threads discussing this on other watch forums. 

*The notable exception being the 7A28-7120 RAF Gen. 1 which uses Promethium lume.