Some children are born with defected iris's. A congenital condition called Coloboma which is a hole or defect of the iris.
The condition will look to the onlooker like there is a round black hole next to or actually in the iris of the eye.
It may not look exactly like a pin hole, it can be a wedge of varying depths at the edge of the eyes. It may give the appearance of an odd shaped pupil if looked at closely. It can also present as a split in the eyes iris running from the pupil to the iris' edge.
How will this affect vision? Well Coloboma of the iris, if detatched from the pupil, may give the sufferer blurred vision, ghosting, or poor visual accuracy, allowing a second image to form and focus on the back of the eye.
It is a condition that will ordinarily be diagnosed just after birth, and it's a defect that can affect the optic nerve, the choroid and the retina. This will normally indicate that its an inherited condition, but it is also a defect that can be caused by surgery to the eye or any kind of eye trauma. Most patients won't be provided with an actual reason for the cause and its unusual for the condition to be related to any other defects. Only a small number of patients that are diagnosed with coloboma will also have other congenital developmental problems.
It would be wise to seek your opticians assistance if you notice your childs pupil is mis-shaped or there appears to be a hole in the iris, If they also complain of decreased or blurry vision medical help should be made priority. Your optician will likely ask for family history and provide a full eye examination. It s possible an MRI scan will be recommended and should be followed up with detailed analysis for the best possible after-care.