Cracked plastic headlamp lens

Hi all,

My Citroen C1 has a small series of cracks on the headlight lens, in a pattern which suggests a stone chip. The cracks seem to go right through the polycarbonate but don't let any moisture in. They are near the centre of the light but don't appear to affect the beam as far as I can tell. (by the way, is that "+" symbol in the centre of the lens supposed to be the centre of the beam?).

Please could you advise as to whether or not this is likely to constitute an MOT fail or advisory?
 
Many thanks,
Robin