uk (Jasper Taylor) writes:
>> I have a pair of soft contact lenses (about 75% water content) which
>> are rapidly silting up with calcium deposits. This didn't happen
>> with my previous pair (38% water). What I'd like to know is, are the
>> deposits made of the same stuff as scale in a kettle, and if so is
>> it feasible to remove them by soaking the lenses in a weak acid?
>This is me, following myself up. I carried out the test over the
>weekend, soaking the lenses in fresh lemon juice filtered through a
>coffee filter for about 24 hours at room temp. Result: No perceptible
>reduction in calcium deposits, and the lenses appear to have taken on
>a slight yellow tinge which is resistant to my 3% H2O2 solution.
>However, they do feel a bit more comfortable now and the yellow is not
>noticeable (to me, anyway!)
>Next I'll try spirit vinegar at an elevated temperature.
>--
>Jasper Taylor                      

>uk (Jasper Taylor) writes:
>>> I have a pair of soft contact lenses (about 75% water content) which
>>> are rapidly silting up with calcium deposits. This didn't happen
>>> with my previous pair (38% water). What I'd like to know is, are the
>>> deposits made of the same stuff as scale in a kettle, and if so is
>>> it feasible to remove them by soaking the lenses in a weak acid?
>>This is me, following myself up. I carried out the test over the
>>weekend, soaking the lenses in fresh lemon juice filtered through a
>>coffee filter for about 24 hours at room temp. Result: No perceptible
>>reduction in calcium deposits, and the lenses appear to have taken on
>>a slight yellow tinge which is resistant to my 3% H2O2 solution.
>>However, they do feel a bit more comfortable now and the yellow is not
>>noticeable (to me, anyway!)
>>Next I'll try spirit vinegar at an elevated temperature.
>>--
>>Jasper Taylor                      
>Have you try something less drastic like putting them into a solution
>of EDTA?
>Regards,
>Teh
>--

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