The two Redeye-species looks a lot like Bluets (Coenagrion and Enallagma species), but they are all black on top of backside of the head. Only young individuals may have faint postocular spots. The Blue-eye has very narrow postocular spots, compared to Coenagrion, but also compared to Enallagma cyathigerum, which it probably resembles most. 

Erythromma lindenii (Selys, 1840), the Goblet-marked damselfly, is a medium-sized (length 30 - 36 mm) blue-and-black (or green-and-black) damselfly in the pond damselfly family (Coenagrionidae). It's a fairly common species in the South and West of Europe but is not found in the British Isles, Scandinavia and Eastern Europe. Erythromma lindenii was previously known as Coenagrion lindenii and Cercion lindenii. The Goblet-marked Damselfly is also known as the Blue-eye. It's an easily recognized species, with its wide antehumeral stripes, narrow postocular spots, the male's very bright-blue eyes. He has very long and curved appendages, and the spear-shaped marks on S3-S6 of his abdomen. The female is most readily distinguished from the similar Enallagma cyathigerum (which has comparably wide antehumerals) by the absence of a vulvar spine underneath S8.

Erythromma lindenii has only small postocular spots on the head, not round as other similar looking genera , but rather thin lines that may be connected across the head. Male E. lindenii very much looks like a Enallagma cyathigerum, but they have longer upper appendages and two dark stripes on side of thorax where E. cyathigerum only have one. The black marking on top of 2nd abdominal segment is also much larger , covering most of that segment's lenght. The markings on the 3rd to 6th segment are long with a "lanceolated" shape. The female E. lindenii has a quite unique coloration, green-yellow but with a hue of blue on the side of the middle of the abdomen. 

It can also be found in Asia: Russian Federation and it is also found in Africa.

Erythromma lindenii has three subspecies: 
              Erythromma lindenii lacustre 
              Erythromma lindenii lindenii 
              Erythromma lindenii zernyi 

Erythromma lindenii is found in southwest and southern Europe and is common around the Mediterranean and in parts of southeast Europe. The species is slowly expanding northwards and does not seem to be threatened. Future threats to the habitat include water pollution, especially in man-made areas that is already at marginal suitability.  IUCN Red List accessed as Least Concern.