Blurred Vision: Could it be linked to my red blood cell count?

I consulted my GP about my vision blurring and general tiredness. An optician's eye examination had shown no eye defect. Blood tests came back normal except for an excess red cell count. This is the second time in two years this has been picked up. Could this cause my symptoms?

Dr Fred Kavalier answers your health question:

When the red blood cell count is too high, the blood becomes thicker. This can lead to small blockages in tiny blood vessels, and this may well explain episodes of blurring of vision. Smokers and people with chronic chest problems sometimes have high red cell counts, but there are other causes that can only be discovered by specialised investigations. Occasionally, the problem can be caused by kidney disease. If your red cell count is persistently high, you need to find out what is going on. Ask for a referral to a consultant haematologist

Please mail your questions for Dr Fred to health@independent.co.uk. He regrets that he is unable to respond personally to questions.