A variety of disorders can cause blurred eyes. For example, if a newborn presents with blurred vision (when the child is crying and vision tests objectively suggest abnormalities), ischaemic-anoxic encephalopathy, congenital genetic disorders, oxygen toxicity, etc. are usually considered. In school-age children, blurred vision should be considered as a congenital disease, a genetic metabolic disease, or tumour compression. People with frequent use of electronic devices and unhealthy eye habits who present with blurred vision should consider refractive error. In older people with blurred vision, refractive errors and cataracts caused by degenerative changes in the lens should be ruled out, followed by vascular and neurological pathologies caused by systemic diseases such as hypertension and diabetes, which may cause blurred vision.