This diagnostic image consists of two side-by-side clinical photographs showing gonioscopy of the anterior chamber angle of the eye under different lighting conditions. The left panel demonstrates the angle with bright illumination and a long slit beam. This lighting causes miosis (pupil constriction), which visually pulls the iris away from the trabecular meshwork, creating the appearance of an open angle. A prominent bright white and orange light reflex is visible across the iris and cornea. The right panel demonstrates the same anterior chamber angle under dim illumination. In these appropriate testing conditions, the lack of light stimulus prevents pupillary constriction, revealing the true state of the angle, which appears closed or significantly narrowed as the iris root approximates the corneal endothelium. The comparison illustrates the clinical importance of controlling ambient light during gonioscopy to avoid false-negative results in angle-closure glaucoma screening.

A close-up clinical photograph of the right eye (oculus dexter, OD) under examination, demonstrating miosis. The image highlights a constricted pupil, approximately 2 mm in diameter, which is circular and displays a sharp corneal light reflex from the slit lamp or illumination source. The iris is visible but partially obscured by reflection. The image is used to document clinical findings in Horner's syndrome, specifically pupillary asymmetry (anisocoria) where the affected eye exhibits miosis. The photograph provides a clear visual of the anterior segment focusing on pupillary size and reactivity for diagnostic purposes in neuro-ophthalmology. Key educational concepts include the assessment of the oculosympathetic pathway and the identification of post-surgical Horner's syndrome manifestations.

A clinical photograph focusing on the left eye of an infant, demonstrating microcoria. The primary finding is a pathologically small, pinpoint pupil (miosis) that is centrally positioned within the iris. The iris appears dark brown and occupies most of the visible corneal area due to the extreme pupillary constriction. The sclera shows some mild periorbital erythema along the eyelid margins, while the palpebral fissure appears narrowed. This visual finding is a hallmark ocular manifestation of Pierson syndrome (congenital nephrotic syndrome with ocular abnormalities), representing a fixed, non-reactive pupil. The image serves as an educational example of congenital ocular pathology and its association with systemic multi-organ syndromes in pediatric patients.

This clinical comparison photograph shows a 47-year-old woman presenting with classic oculofacial features of Horner’s syndrome following a clavicle fracture. Image A demonstrates the acute presentation of the oculosympathetic defect in the left eye, characterized by significant blepharoptosis (drooping of the upper eyelid) and ipsilateral miosis (constriction of the pupil) compared to the normal right eye. A red arrow points to the affected left eye to emphasize these findings. Image B shows the same patient at a three-month follow-up after surgical fixation of the fracture. It illustrates complete resolution of the syndrome, with symmetric eyelid positions and equal pupillary diameters (isocoria) in both eyes. This visual progression highlights the classic clinical triad (ptosis and miosis, with anhidrosis typically associated) and the potential for recovery following the management of the underlying traumatic compression of the preganglionic sympathetic pathway. The image is a valuable educational resource for neurology, ophthalmology, and trauma surgery.