The accurate identification of eye tumors continues to be a difficult medical diagnostic problem. The several non-nuclear clinical diagnostic techniques that have been used, such as direct and indirect ophthalmoscopy, slit lamp examination, transillumination, fluorescein angiograph, ultrasonography and direct analysis of the subretinal fluid, have all resulted in a high percentage of misdiagnoses. This has resulted in eyes being enucleated that did not contain malignant melanomas, but more tragically, eyes with malignant tumors were not enucleated, resulting in the death of the patient due to the metastatic spread of the tumor. At the present state of development, the 32p uptake test offers the best diagnostic method. For tumors of the uveal tract both G. M. and semiconductor detectors can be used. Detectors more sensitive to lower energy betas are needed to diagnose deeper lying tumors and to study the possible correlation between percent 32p uptake and the particular cell type of the tumor.