noun (n)

• an eye having a single lens(noun.body)

  Synonym:
  simple eye, stemma
  

  source: wordnet30
• an eyelike marking (as on the wings of some butterflies); usually a spot of color inside a ring of another color(noun.attribute)

  Synonym:
  eyespot
  

  source: wordnet30
• A little eye; a minute simple eye found in many invertebrates.(noun)

  source: webster1913