Eyes & Eye-like Structures

Several groups of oribatid mites appear to have independently evolved a new type of light sensitive organ called the lenticulus.  This structure is median, unpaired and often a simple oval of lightly colored cuticle, but may have a distinct convex lens.  It is usually situated at the anterior edge of the notogaster.  Some early derivative acariform mites also have a single median eye, often  hidden under a nose-like process above the chelicerae called the naso.