Like most healthcare professions, the education and certification of optometrists is regulated in most countries. Optometric professionals and optometry-related organizations interact with governmental agencies, other healthcare professionals, and the community to deliver eye- and vision-care.
The average length of an erect penis is 5.16 inches (13.12 centimeters) and the average circumference is 4.59 inches (11.66 centimeters), according to a new analysis of penis length studies involving more than 15,000 men around the world.
It varies per person, and per ethnicity. Average vagina is about 3 to 3.5 inches deep when unaroused, but it can lengthen and widen several inches with arousal and childbirth (usually around 7 inches deep with arousal). The average penis is only 5.5-6.5 inches, and less than 1% of the population has a penis over 8 inches.