Average wingspans range from 29mm - 31mm. The underwings of the male are a deep-blue with clear-white edging, with a contrasting black border, noticeably wider than other blues. Underneath the hind wing a broad band of orange links a series of black spots with green pupils, hence the name. The females are similar though generally darker.

The males will fly close to the ground during July to August and have a life expectancy of approximately three days , the female three to four days. During this period the male establishes a territory within the closed butterfly colony.

White, disc-shaped eggs, covered in tiny spikes, are deposited on specific food plants such as heather ( Calluna vulgaris), Gorses( Ulex spp.) and bird’s - foot trefoil(Lotus corniculatus). The caterpillars, which are green with a black stripe across the back and olive-white stripes along the sides, secrete sugars, and amino acids from their honey glands. This secretion also contains a precursor to formic acid, used by ants as a means of protection.

The larvae are rarely seen without these attending ants, Lasius niger, or Lasius alienus and are usually found within the ants' nests, where they feed and pupate.