A founding member of the American Medical Association, and the first president of the Philadelphia Ophthalmological Society, Hays published the first study of non-congential colorblindness and the first case of astigmatism in America.

He later moved to the Pennsylvania Infirmary for Diseases of the Eye and Ear, and upon its opening in 1834 joined the staff of the Wills Hospital for the Relief of the Indigent Blind and Lame.

[4] During his stint at the Pennsylvania Infirmary, Hays wrote medical articles and contributed a chapter to William Potts Dewees's textbook Practice of Medicine (1833).

At Wills, Hays published the first study of noncongenital color blindness, reported the first case of astigmatism in America, and devised a needle-knife for cataract surgery.

[7] He joined Nathaniel Chapman's staff in 1820 (then called the Philadelphia Journal of Medical and Physical Sciences), became the sole editor in 1841, and upon his retirement passed the editorial duties to his son, I. Minis Hays.

In 1830, John D. Godman described a fossil specimen from Orange County, NY, as a new type of elephant, dubbing it Tetracaulodon.

Across the Atlantic, Richard Owen initially joined Godman's camp and English transplant George Featherstonhaugh lectured in support of the juvenile mastodon theory that eventually prevailed worldwide.

[21] An old Savannah family, the Minises were among forty-one Jewish settlers who departed England in 1733[22] and Philip Minis (Sarah's paternal grandfather) had the distinction of being the first white child born in Georgia.