The Inami Mod-R Head Mount Applanation Tonometer operates according to the 'Goldmann method', by measuring intraocular pressure from the force required to flatten (applanate) a constant area of the cornea.

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The R-Type model, which fits most slit lamps and uses applanation prisms,  ‘swings in’ and can be permanently left mounted on the post that fits to the eyepiece assembly.​