Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Severe eye pain, major eye trauma, or a chemical injury also needs emergency care.
These symptoms are not expected from a stable iris coloboma and may signal a separate problem that needs rapid treatment.
Arrange prompt eye care if there is a new change in vision, increasing glare, eye redness, discharge, or discomfort.
Contact lens wearers should remove the lens and seek prompt advice for pain, marked redness, light sensitivity, or blurred vision.
Sudden loss of vision, a curtain or shadow across the visual field, a sudden burst of new floaters, or repeated flashes of light requires urgent same-day eye assessment.
Follow-up depends on age, vision, and whether the coloboma affects structures beyond the iris.
Routine visits may include vision testing, an updated glasses prescription, eye-pressure measurement, and a dilated retinal examination.
Adults with a stable, isolated iris coloboma may need only routine eye care.
More frequent monitoring may be advised for glaucoma, cataract, retinal involvement, or previous eye surgery.
The article also says
Children generally need regular monitoring while vision is developing.
Appointments are important even if the child does not report symptoms, because refractive errors and amblyopia may not be obvious at home.
Parents and caregivers should also follow recommendations for glasses, patching, or school accommodations.
Every sign above is quoted from the sofidex article on Coloboma of the iris. If you are not sure, err upward — it is always reasonable to be checked.