My contact lens prescription regularly fluctuates. Both eyes are usually around +6.0, occasionally +6.5, most of the time they're stable and drift just a little.
Around once a year my eyes undergo significant fluctuations. In the past two weeks my eyes have dropped from +6.5R +6.0L to +4.75R and +5.0L. They may reach as low as +4.5. I expect in 1-2 weeks they'll go back up toward +6.0. This has been happening for years. I have every contact lens strength from +4.5 to +6.5.
I see a good optometrist at least annually, he's looked at my eyes in both states, and he has no idea what's going on. He sent me to a doctor for a diabetes test, the doctor asked me a series of questions then said it wasn't even worth doing the blood test.
One change to my diet recently: I have started eating cereal with yoghurt for breakfast instead of eggs with cheese, and I've started eating more chocolate. My body seems to work better on protein and fat, but cereal's easier and everyone likes chocolate. My eye fluctuations appear to have started before the diet change. I've also started eating more gluten, which until not long ago I was actively trying to avoid, just to see what happened. When I eat low sugar low gluten/carb I tend to lose weight.
Can anyone suggest if this fluctuation is a problem, and how I should go about diagnosing the cause?
If your A1C test was normal you do not have diabetes. I would suggest you see a Eye Md ophthalmologist that specializes in cornea/refractive surgery. Don't wear your contacts for 2-3 weeks before seeing him/her. They will do a cornal topography test. You can ask about whether you should continue contacts with this history; wear glasses or consider hyperopic refractive surgery.
JCH MD