She is a clinical attending at the New England Eye Institute. She was formerly the senior optometrist at the Boston Foundation for Sight, where she exclusively designed and fit scleral lenses for irregular corneas and complex corneal disease. She is a fellow of the American Academy of Optometry, a fellow of the Scleral Lens Education Society, and a fellow of the British Contact Lens Association. She serves as a clinical and education consultant for Bausch + Lomb. Dr. Johns speaks nationally and internationally on specialty contact lenses, irregular corneas, and severe ocular surface disease.