He wrote Practical Treatise of the Diseases of the Eye, one of the first British textbooks of ophthalmology.

He obtained his medical doctorate under Georg Joseph Beer at the University of Vienna, and returned to Britain in 1848.

In 1849, Mackenzie also assumed the anatomy chair at Anderson's College Medical School.

MacKenzie died at Glasgow of angina pectoris on 30 July 1868, leaving a widow and one son.

[4] MacKenzie was the mentor of Thomas Wharton Jones, leading to a significant scientific genealogy including physicists such as Paul Dirac and Stephen Hawking.