From the Research
Photopsia, or light flashes near dissociation, can be caused by a range of conditions, from common refractive errors to rare neurological disorders, with the most recent evidence suggesting a link between visual distortions and dissociative experiences 1. The causes of photopsia can be categorized from common to rare, with common causes including:
- Uncorrected refractive errors such as myopia, hyperopia, or astigmatism, which affect how light focuses on the retina
- Presbyopia, the age-related loss of near focusing ability, typically affecting people over 40
- Binocular vision disorders like convergence insufficiency, where the eyes struggle to work together at near distances Less common causes include:
- Accommodative dysfunction, where the eye's focusing mechanism works improperly
- Certain medications that affect pupil size or accommodation, such as anticholinergics or sympathomimetics Rare causes include:
- Neurological conditions affecting visual pathways, such as multiple sclerosis or brain tumors
- Ocular surface diseases disrupting the tear film
- Retinal disorders like macular degeneration
- Pituitary apoplexy, which can cause sudden visual loss and light-near dissociation of the pupils 2
- The Argyll Robertson pupil, a condition characterized by a pupil that is small and constricts poorly to direct light but briskly when a target within reading distance is viewed 3
- Holmes-Adie syndrome, a rare neurological disorder that can cause light-near dissociation, vermiform iris movements, and absent deep tendon reflexes 4 It is essential to note that the exact cause of photopsia can only be determined through a comprehensive medical evaluation, and treatment should be guided by the underlying cause, with the goal of improving morbidity, mortality, and quality of life outcomes 5.