Diagnostic apparatus for diagnosing eye diseases and dysfunctions for medical use; optometric instruments for determining eye misalignment and vergence insufficiency; apparatus to diagnose strabismus for prism to be implemented in spectacle lenses for medical purposes; apparatus for measuring and diagnosing strabismus, trigeminal dysphoria, vergence insufficiency and ocular misalignment in order to determine prescription for contoured prism eyeglass lenses to alleviate symptoms of misalignment and to provide relief for hard-working eyes for medical purposes; apparatus for measuring and diagnosing strabismus, trigeminal dysphoria and ocular misalignment in order to determine lens prescription for eyeglasses to relieve symptoms of eyestrain resulting from use of digital devices for medical purposes; apparatus for measuring and diagnosing strabismus, trigeminal dysphoria, vergence insufficiency and ocular misalignment in order to determine eyeglass prescription to relieve the symptoms of eye fatigue, headaches, neck pain, and shoulder pain for medical purposes; optometric measurement instrument to determine prescription for computer glasses and digital glasses prism by measuring ocular misalignment for medical purposes; apparatus for measuring and diagnosing trigeminal dysphoria in order to determine lens prescription to treat trigeminal dysphoria for medical purposes; optometric measurement instrument to assist the prescription of contact lenses with prism or contour prism by measuring ocular misalignment for medical purposes; optometric instrument for measuring ocular motility for medical purposes; optometric instrument for pupillometry for medical purposes; optometric instrument for measuring afferent pupillary response for medical purposes; optometric instrument for saccadic eye movement assessment for medical purposes; optometric instrument for measuring smooth pursuits of the eye for medical purposes