Scotopic Pupil Size in Myopia and Hypermetropia

Background: The pupil is responsible for forming the physical aperture stop of the eye's optical system, which regulates the quality of images and retinal illuminance. At roughly 3-5 mm pupil sizes, the corrected eye's retinal image quality is at its best. Below and above this range, respectively, diffraction and higher-order aberrations lead to quality degradation.Aim: To ascertain the relationship between pupil size and refractive error and to determine size of the pupil in myopes and hypermetropes as well as the relationship between this refractive error and pupil sizePatients and Methods: In the ophthalmology departments of Al-Zahraa University Hospital and Qalawoon Hospital in Cairo, Egypt, a prospective observational analytical study was carried out from May 2023 until the sample was processed. One hundred patients' pupil size was measured.Results: Myopic patients have larger pupils than hypermetropic patients, who have smaller pupils. Our research strengthens the evidence showing that refractive error impacts pupil size, with large pupils in myopia and small pupils in hypermetropia.Conclusion: Refractive error impacts pupil size, causing a large pupil in myopia and a small pupil in hypermetropia. Before any surgery, it is crucial to measure the pupil's size because patients with large pupils run the risk of developing spherical aberrations, halos, and starbursts around light after the procedure.