Isodose curves for 125 I ophthalmic application in different geometry and activity can be obtained using the empirical formula based on suitable geometric model. The results of surface dose rate determined with lithium fluoride (LiF) thermoluminescent dosimeter (TLD’s) chips in water-organic glass phantom and air had no obvious difference and the surface dose rate and its uniformity

(3.46±0.011) and (0.178±0.15)nGy/h·10 7Bq were obtained. Count measurements and dose determinations for the front and back etc. of the ophthalmic applicator with BaF 2 scintillation detector and LiF TLD’s had revealed the space distribution of dose for 125 I ophthalmic applicator in which dose on the back was less than 0.1% of that on the front. The distribution of the absorbed dose rate along the eye axis had been measured using LiF TLD’s in water-organic glass phantom. The measured and calculated dose data indicated that when measuring distances were larger than about 5mm the experimental results agreed with those from calculation within the range of error

otherwise the measured values were lower

still it could be explained by experimental conditions.