Tab. I.

Most prevalent eye conditions causing vision impairment.

Ocular condition	Description	Epidemiology	Treatment	References
Cataract	Opacities in lens obstruct or scatter the incoming light	It is the most important cause of blindness worldwide (17.8 million in 2020) and the second leading cause of moderate or severe vision impairment (83.2 million). Cataract results from age-related changes, smoking, UV damage, dehydration crisis, diabetes, galactosemia, and steroid use	Surgery with intraocular lens (IOL) implantation	[2]
Refractive error	Blurred vision because light is not sharply focused on the retina, due to a mismatch between the eye axial length and the refractive power of the cornea and/or lens. Hypermetropia (long sight) and myopia (short sight)	It is the second main cause of blindness (3.7 million) and the main cause of vision impairment (157.5 million)	Refractive error can be corrected using spectacles, contact lenses, IOL implantation during cataract surgery or laser refractive surgery	[10, 11]
Glaucoma	Progressive damage of the optic nerve in one or both eyes, resulting in irreversible blindness	The third main cause of blindness (3.6 million) and the fourth cause of moderate or severe vision impairment (4.1 million). The risk of developing glaucoma increases with age and is increasing globally with population ageing	Medication, trabeculoplasty, iridotomy, or surgery	[2, 12]
AMD	Degeneration of the macula, resulting in loss of clear vision. It has both “dry” and “wet” forms	The fourth prominent cause of blindness globally (1.9 million) and the third in moderate to severe vision impairment (6.2 million). AMD is the primary cause of vision loss in high-income countries	Long term anti-VEGF intravitreal injections	[13-15]
DR	Damage to the small blood vessels in the retina leads to leakage of plasma fluid and blood, which may damage central vision (“diabetic macular oedema, DMO”)	The fifth cause of blindness (1.1 million) and vision impairment (3.8 million)	Retinal laser; intravitreal injection of anti-VEGF or steroid; retinal surgery	[8]