A synechia is an eye condition where the iris adheres to the either the cornea (i.e. anterior synechia) or lens (i.e. posterior synechia). Synechiae can be caused by ocular trauma or iritis and lead to certain types of glaucoma. It is sometimes visible on careful examination but usually more easily through an ophthalmoscope or slit-lamp.
Mydriatic/cycloplegic agents, such as topical atropine, are useful in breaking and preventing the formation of posterior synechia by keeping the iris mobile. Dilation of the pupil in an eye with synechia can cause the pupil to take an irregular (non-circular) shape as shown in the photograph. If the pupil can be fully dilated during the treatment of iritis, the prognosis for recovery from synechia is good. This is a treatable status.