Saw another iritis misdiagnosed as conjunctivitis.  Detecting cell and flare is tough, and this video is pretty good.   Again severe pain and consensual photophobia do not jibe with conjunctivitis. 

http://www.youtube.com/watch?v=grzPDD29FoU

Some more basics (from CK)

Iritis = anterior uveitis. Causes- infection, autoimmune, unknown.

Exam: Diffuse perilimbal injection increasing towards the limbus (reversed in conjuncitivits). [limbus is junction of cornea and sclera]

     Can have decreased visual acutity (normal in conjunctivitis)

     Miosis commonly present

     Direct and consensual photophobia (direct only with conjuncitivits) 

Refer to ophtho within 24 hours (untreated can form posterior synechiae (adhesions between iris and lens) blocking aqueous humor flow causing glaucoma

Treat with cycloplegics and topical steroids

Iritis                                        Conjuncitivis