Name	Info	Provider	Link
Eye Care	free resource	MedlinePlus Health Information	https://medlineplus.gov/eyecare.html
Cited by Patents in	free resource	The Lens - Patent Citations Database	https://www.lens.org/lens/search/patent/list?q=reference_cited.nlp.ids.pmid:3081459
	subscription/membership/fee required	Silverchair Information Systems	https://iovs.arvojournals.org/article.aspx?volume=27&issue=3&page=419