**Core Concept**
The School vision screening programme aims to detect vision problems in children early on, enabling timely intervention and treatment to prevent long-term visual impairment. This programme typically involves a series of tests to assess visual acuity, eye alignment, and other aspects of vision.

**Why the Correct Answer is Right**
The correct answer is a trained teacher or a school nurse, who is trained to perform simple vision tests such as visual acuity charts and cover tests. These individuals can identify children with potential vision problems and refer them to an eye care professional for further evaluation and treatment. The tests used in the School vision screening programme are designed to be quick, easy, and non-invasive, making it feasible for non-medical personnel to administer them.

**Why Each Wrong Option is Incorrect**
**Option A:** A pediatrician, while a medical professional, is not typically involved in the School vision screening programme due to the large number of children that need to be screened and the need for rapid identification of potential vision problems.
**Option B:** An optometrist or ophthalmologist, while experts in eye care, are typically not involved in the School vision screening programme, which is designed to be a preliminary screening process rather than a comprehensive eye examination.
**Option C:** A nurse practitioner may be involved in the School vision screening programme, but the programme typically relies on trained teachers or school nurses to perform the vision tests, rather than registered nurses with advanced training.

**Clinical Pearl / High-Yield Fact**
The School vision screening programme is an essential tool in identifying children with vision problems early on, and it is crucial for parents and caregivers to be aware of the signs and symptoms of vision problems in children, such as squinting, headaches, or difficulty seeing distant objects.

**Correct Answer:** C. A trained teacher or school nurse.