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24 May 2012

Answer to Question #6177 Submitted to "Ask the Experts"

Category: Radiation Effects — Effects on Tissues and Organs

The following question was answered by an expert in the appropriate field:

What threshold of radiation would be necessary (or possible) to cause nuclear anterior eye cataracts? In the last few years I have had nuclear scanning for my heart, CT scans twice for sinus problems, chest x rays, and numerous dental x rays. Does this seem like enough total radiation to have possibly caused the cataracts?

Available evidence indicates that the probability of radiation-induced cataract is proportional to dose and to dose rate. At a very high dose rate there appears to be a threshold of about 500 millisievert (mSv). This high dose rate is encountered only in events such as nuclear war, nuclear accident, or radiation therapy for cancer. If the dose is delivered over a period of months to years (as in your case), a much larger total dose is required—5,000 mSv or more.

Conclusion: Your radiation exposure has not been sufficient to produce cataract.

S. Julian Gibbs, DDS, PhD

Answer posted on 26 February 2007. The information and material posted on this website is intended as general reference information only. Specific facts and circumstances may alter the concepts and applications of materials and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice specific to whatever facts and circumstances are presented in any given situation. Answers are correct at the time they are posted on the Website. Be advised that over time, some requirements could change, new data could be made available, or Internet links could change. For answers that have been posted for several months or longer, please check the current status of the posted information prior to using the responses for specific applications.