When Dad was in the hospital a few weeks ago, he got an eye infection which prompted a long visit to the Eye clinic.

It was determined that Dad has glaucoma, and the doctor prescribed eye drops for him to take every day for the rest of his life to preserve what little sight he has remaining in his left eye, and keep the right one from getting worse.

Dad does not like eye drops.  He complained every day for the first week.

So I decided to tell him that they gave him the drops to prevent glaucoma since he just turned eighty.

Now he does not complain anymore because he "sure does not want to lose his perfect sight."

That fiblet worked like a charm!