A decentred pupil refers to a pupil that is not centered in the iris, often due to trauma, surgery, or certain eye conditions.

Possible causes:

1. Trauma or injury
2. Surgical complications
3. Congenital conditions
4. Uveitis or inflammation
5. Synechiae (adhesions)

Effects:

1. Vision disturbances
2. Increased sensitivity to light
3. Cosmetic concerns