Evaluation of Optical and Radiation Protection Parameters of High Refractive Index Polymers

Abstract

The optical properties of the prescription and non-prescription (plano) samples of the MR-8 high index lens were examined by UV/VIS spectrometry. The results showed that the light transmittance of the two MR-8 lens samples examined was over 90%, and the transmittance at the wavelength (~550nm) to which the human eye is most sensitive was 83.437% and 84.602% for the prescription and non-prescription samples, respectively. In terms of quality of vision, it is expected that the visible light transmittance will be high and the ultraviolet light transmittance will be minimal. It is very important that both the prescription and non-prescription organic MR-8 lenses tested have no transmittance below approximately 398nm. This means that this lens material protects against UVA and UVB rays, even though it is uncoated. It is also important to reduce the dose to the lens, which is a radiosensitive tissue. In the study, the mass absorption coefficients of MR-8 and Ormix lens materials in the 0.15-2.00 MeV energy range were calculated using the web-based XCOM programme. LAC, HVL, TVL, MFP, RPE and TF values were calculated from the MAC values obtained. At energies below 0.05 MeV, the maximum MAC value was 0.974 and 4.416 for the MR-8 and Ormix lenses, respectively. The RPE and TF values were 0.807-16.235%, 0.996-0.992% for the MR-8 lens and 0.862-55.233%, 0.448-0.991% for the Ormix lens. The results showed that the photon absorption ability of the Ormix lens is relatively better in the region where the photoelectric interaction is dominant. This research is also important in terms of determining the optical and nuclear radiation parameters of the material used in the manufacture of high index lenses and investigating its effectiveness in reducing the dose to the eyepiece.