Battling on through the joys of DES as one does, it occurred to me that I wasn't sure about the role of humidity. My understanding is that for those with either AD or MGD (or both as in my case), humidity is a big factor for eye comfort.
My office registered 33% relative humidity when I measured last week which is pretty low and I need to look into why that is (though I'm not sure my hygrometer is accurate).
But, I'm not sure whether we're talking about relative humidity (RH) or absolute humidity (AH) when it comes down to helping DES. Relative humidity (for the sake of simplicity) is how much water vapour is in the air compared to how much the air can hold (the temperature affects this), whereas absolute is simply how much water vapour there is.
So, if the RH is 50% and the air temp is 25C, if the air temp goes down to 20C, the RH will go up - even though there may not be any more water vapour around. But the AH remains the same in both situations. Over the day, the office temperature went up, and as it did so, the RH went down. But did this have much real effect from a DES sufferer's point of view?
So mostly look at RH hen understanding how favourable the environment is for a DES sufferer (and I guess wind, dust etc) - or is this totally misleading given the wide fluctuation RH has related to the temperature?
I also appreciate that temperature has an impact on tear film evaporative rates.
My office registered 33% relative humidity when I measured last week which is pretty low and I need to look into why that is (though I'm not sure my hygrometer is accurate).
But, I'm not sure whether we're talking about relative humidity (RH) or absolute humidity (AH) when it comes down to helping DES. Relative humidity (for the sake of simplicity) is how much water vapour is in the air compared to how much the air can hold (the temperature affects this), whereas absolute is simply how much water vapour there is.
So, if the RH is 50% and the air temp is 25C, if the air temp goes down to 20C, the RH will go up - even though there may not be any more water vapour around. But the AH remains the same in both situations. Over the day, the office temperature went up, and as it did so, the RH went down. But did this have much real effect from a DES sufferer's point of view?
So mostly look at RH hen understanding how favourable the environment is for a DES sufferer (and I guess wind, dust etc) - or is this totally misleading given the wide fluctuation RH has related to the temperature?
I also appreciate that temperature has an impact on tear film evaporative rates.
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