What is the most common cause of blurred vision?

Blurred vision is frequently caused by refractive errors, which are defects in the eye's ability to focus light properly. Common types of refractive errors include myopia (nearsightedness), hyperopia (farsightedness), and astigmatism. These issues typically arise due to the shape of the eye affecting how light is focused on the retina, leading to a lack of clarity in vision. Since refractive errors are widespread and can easily be corrected with glasses or contact lenses, they represent the most common cause of blurred vision encountered in clinical practice.

Other conditions like macular degeneration, cataracts, and glaucoma can also lead to blurred vision but are generally associated with specific age-related changes, lens opacities, or increased intraocular pressure, respectively. These conditions tend to be less prevalent compared to refractive errors and often occur in older populations or those with risk factors, which makes refractive errors the primary culprit in most cases of blurred vision.