Answer to Question #5660 Submitted to "Ask the Experts"

I am a student radiographer and I am concerned about eye protection. I know that there is a link with occupational exposure and cataracts but very few people wear eye protection. It seems almost silly wearing the apron and thyroid collar and then leaving the eyes exposed (particularly in fluoroscopy and c-arm environments). Can you shed some light on this? Do you feel that the cost of the protective glasses is worth the expense?

You are a very perceptive student and raise an excellent question. From an experience standpoint, there are two main reasons for the low use of leaded glasses: (1) the glasses are typically very heavy and difficult to wear and (2) lens-of-the-eye doses are typically low enough to not be an issue.
To clarify the second point, remember that in most states, the whole-body dose limit is 5 rem per year, while the lens-of-the-eye dose limit is 15 rem per year and the difference in these limits is due to the difference in risk of radiation-induced effects. Experience has shown that the number of workers who approach these dose limits in x-ray environments is small compared to the total number of workers, and the individuals typically approach the whole-body dose limit before they approach the lens-of-the-eye limit (collar dosimeter readings for whole body and lens of the eye are usually about the same for x-ray use).

Most states also require a lead apron to be worn during fluoroscopy procedures, but not lead glasses.  Also, keep in mind that if most individuals are nowhere near the dose limit for the lens of eyes (or even near ALARA trigger levels which are typically set at 10% and 30% of the dose limits on a quarterly basis), then the "R" for "Reasonable" kicks in regarding use of lead glasses. The radiation dose is significantly lower than the dose limit, and the dose limit is considered to be set at some safe level below which effects can occur, and the lead glasses are cumbersome and, therefore, not typically worn.

As far as the use of lead glasses, I recommend that individuals try a pair for a while to see if they will wear them. Most facilities buy them and after a while they never get used (except by individuals who need to wear them due to higher lens-of-the-eye doses). If you can access a pair to test drive and decide that you are willing to wear them, then I believe they are worth the expense.

Ken "Duke" Lovins, CHP