[Mbmyco2]

Is potato blight the brown marks on the skin of my potatoes and is it still ok to eat them?

[mumofstig]

If your top foliage was ok it isn't blight - a photo might help 

[Kleftiwallah]

If only on the surface it sounds like potato scab.  Still edible after peeling.  Brown areas within the potato is a problem called spraing, not nice to look at but still edible.

Cheers,  Tony.