When you hear National Health specks do you imagine glasses in the style that John Lennon wore (round, wire-rimmed) or do you picture them as the Jarvis Cocker style (fat, black rims).
I don't know why, but the fat, black rimmed style reminds me of 'NHS', and the round, wire-rimmed style reminds me more of 'Nazi Officer'.
The standard National Health frames were the nerdy plastic frames. The round type actually had plastic covering the rim and curled around the ears to prevent falling off when active. For this reason they were given to children and to members of the armed forces - I assume the German army used a similarly practical style. Lennon first wore them when playing Private Gripweed in the film 'How I Won the War', and was taken with the style and had a more practical and stylish version made. They quickly became an indispensible fashion accessory...
I remeber the kiddies style as being round and pink for girls and blue for boys. My mother was horrified at me wearing NHS specs as a child so we had some private ones - I feel I was duped here as photos show me loking like an 8 year old Dame Edna Everage!