According to the World Health Organization, as of October 2019, approximately 2.2 billion people worldwide were affected by vision impairment or blindness, with at least 1 billion having unaddressed or preventable conditions. According to the Vision Loss Expert Group, 12% of blindness or vision impairment was caused by refractive error, 6.3% by cataract, 0.7% by glaucoma, 0.4% by...