Sorry, my doctor took the photograph on her phone.
Sorry my phone is old & I don't know how to take a photo on my camera & email it.
The line is in the middle of my tongue, & there is pink right down the absolute centre. Now looking in a mirror I can see a space and two further lines , ie. one each side of the centre black line. Sorry but I have no idea of measurement, but the lines on the sides of my tongue were not there prior to eating I am almost certain.
Absolutely no soreness, tenderness or anything. However, the whole of my tongue doesn't look normal, its not hairy, its not all black but the remainder of the tongue doesn't look healthy pink like it should.