Redness at Base of Irises

Your question offers very little information to help diagnose the condition. You did not provide the age of the patient nor any other symptoms.

For instance, if the lower lids don't come up to the "bottom rim of both irises," also called the limbus, this could be poor closure of the lids and an exposure of the lower limbus to drying and irritation or even infection. Or, this may be caused by lower lid irritation from dysfunction of the oil glands (also called meibomian glands) of the lower lids, or a low grade infection of the lashes of the lower lid called blepharitis.

There are many other causes and this should be evaluated by an ophthalmologist to treat successfully.