New instrument for the quantitative determination of passive forced traction.

An instrument for the quantitative analysis of the passive forced traction test on strabismic patients under anesthesia is described. This spring dynamometer measures the grams of force required to displace the eye from its rest position into the various fields of rotation of the globe. Measurements on a control population are compared with both non-restrictive and restrictive strabismic patients. Characteristics of various types of restrictions encountered are mentioned as an aid to more precise diagnosis of specific strabismic problems.