Yes, Kevin.  Orbital Cellulitis is largely a clinical problem in children.

Most adults who have conjunctivitis, only have conjunctivitis.  However...same caveat.  If the eye is PAINFUL, and light sensitive, in adults that may mean the Iris of the eye is involved (a much more serious condition, known as Iritis..untreated, this can certainly lead to terrible complications and blindness).  Sooo...again, medical consultation would be more emergent with that scenario than an itchy red eye. 

Unfortunately, as in all of medicine, some malignant conditions start out fairly innocuously, so it is ALWAYS prudent to seek medical attention, rather than waiting, or trying home remedies.

Gene