Equipment and supply responsibilities include cleaning, maintaining, and calibrating ophthalmic instruments such as slit lamps, lenses, ophthalmoscopes, and diagnostic devices; packaging and sterilizing reusable instruments using approved methods; arranging for repairs or recalibrations as needed; and ensuring all supplies, instruments, and medications are properly stocked, sterile, and readily available. Additional technical responsibilities performed under provider direction include manual and automatic keratometry, retinoscopy, refractometry, Potential Acuity Meter testing, visual field testing, fundus and anterior segment photography, external photography, A-scan and B-scan ultrasonography, and the removal, cleaning, and insertion of contact lenses.