This can be accomplished through careful attention to radiation dose exposure. The greatest concern about the nonstochastic effect of long-term occupational exposure is the formation of cataracts. Cataracts usually form after a latent period of several years. The recommended maximum exposure to the eye lens is 15 rems per year. Eye protection is therefore warranted.
Leaded eyeglasses help reduce the exposure risk.
The film badge basically contains a piece of x-ray film. The magnitude of exposure to x-rays is derived based on the density of the exposed photographic film within the badge compared with densities from film that has had known amounts of exposure. The TLD badge contains a disk with lithium fluoride crystals. The lithium fluoride crystal absorbs the x-rays, raising the electrons to a higher state. When heated, the electrons in the crystal return to their baseline state, releasing light in proportion to the x-ray exposure.