This video is unavailable because we were unable to load a message from our sponsors. If you are using ad-blocking software, please disable it and reload the page. Embed Code Restart Playing WATCH MORE VIDEOS FROM THIS EPISODE > Ophthalmologist Dr. Kerry Assil explains how cataracts develop and how the lens of the eye hardens as we age. Inevitably, there comes a time when the lens will need to be replaced. It's not a matter of if, it's a matter of when, he states. ShareTweet