August 16, 2018 at 8:02 PM by Dr. Drang
So often it’s the little things. A few months ago, I made a small change in how I pack for overnight trips, and it’s eliminated a nagging doubt I used to have.
I use the Clear Care system to disinfect my contact lenses. Every night, I put the lenses in a plastic holder which then goes into a cup of hydrogen peroxide solution.
The holder is integral with the screw-on cap. The left lens goes in the holder on the white side, the right lens on the blue side. Before putting the holder into the cup and screwing it tight, I fill the cup with solution up to the embossed line. And that’s where the doubt came in.
Clear Care’s travel bottles contain 3 ounces of solution, the maximum allowed by the TSA. The problem is that the bottles are opaque, so after I’d used one a few times, I wouldn’t be sure how much was left in the bottle. I could shake the bottle and kind of tell if there was more or less than half left, but beyond that I had no idea. So I’d often find myself standing in my bathroom while packing for a trip, trying to decide whether there was likely to be enough in the bottle to make it through however many nights I’d be away. More often than not, I’d pack a new bottle just to be sure. The solution wouldn’t go to waste—I’d use the travel bottle at home until it was empty—the waste was of my time and attention.
Eventually, I realized that this was both stupid and easily solved. One day, when I had just replaced an old cup and holder with a new one, I took the old cup into work with me to do some measuring.
One of the advantages of working in a company with a chemist is that she keeps a variety of graduated cylinders in the lab cabinets. I didn’t take long to learn that the contacts cup is 9.6 ml up to the embossed line. As I said, the travel bottle is 3 oz or 90 ml, so in theory, I could get 9 nights of use from the travel bottle. But because I sometimes fill the cup beyond the line—and I really don’t want to find myself at a hotel late at night without enough cleaner—I limit myself to 8 nights per bottle.
What sophisticated technological system do I use to keep track of how much solution I’ve used? I write “8” in on the side of each travel bottle and make a tally mark every time I use it. I keep a blue Sharpie in my shaving kit for this.
As long as I can subtract, I’ll have peace of mind.