Not true. Pub Med.gov 2008 showed after 1 hour, basically healthy surgeons had decreased SpO2 and increased heart rate. I've been an RN x 27 years and found wearing masks difficult at best, suffocating at worst. Here's the link. And this one isn't tainted by politics.

If this is true, then why are my RBC and HCT blood test results high when wearing a mask as compared to not wearing a mask? Does a regular mask stop a virus? Can the virus enter the body through our eyes?

Rather than looking at articles... Let's look at meta analysis of studies
www. ncbi.nlm.nih. gov/pmc/articles/PMC8072811/

Yes, a mask poses no risk of hypoxemia in healthy people. However, if you are already dealing with hypoxemia associated with pulmonary function deficits that plays a role in driving up your blood pressure? Masking causes some cardiopulmonary stress, which may be trivial for healthy people, but not for everyone. Masking increases air resistance, which requires greater respiratory effort and increases the dead space and a corresponding amount of air that is rebreathed by 50 to over 100%. The gas molecules in the dead zone can easily go through the pores of a mask, but there is only a limited exchange of air via passive diffusion in what might be a split second between the end of one exhalation and beginning of the next inhalation.

I can't tolerate wearing a mask unless I get supplemental oxygen, which is provided by my primary doctor. But no one else is willing to make that accommodation. After accommodation is refused, I am told that I am trespassing and must leave the facility immediately. Insurance won't cover oxygen because I do not meet their criteria and I couldn't afford to buy or rent oxygen concentrators. I have not been able to get IVIG infusion recommended by a CLL speciaist since the mask requirements were imposed.

However, I could not be turned away from an emergency department nor forced to mask up without oxygen in that setting. I had to repeatedly tell hospital employees that a mask rule does not trump the imperative to not harm the patients, and masking without oxgyen is harmful to me The diagnoses abdominal cellulitis and strep A was detected with a rapid strep test. Blood pressure was high enough to be concerning but not emergent, eg 192 / 84, However, the doctor order tropinin, NT PROBNP, venous blood gasses and an ECG. Venous blood oxygen saturation was 54%, with normal range of 94 to 100%. First abnormal ECG of my lifetime, interpreted as showing an incomplete right bundle branch block,

When I put on a mask, I begin to experience a headache and nausea within minutes.
The longer I wear the mask, the worse those symptoms get and longer it takes for those symptoms to resolve. These are familar symptoms of high blood pressure.

In October 2020 I used a pulse oximeter and automated blood pressure cuff to monitor changes in pulse, oxygen saturation and blood pressure at home to evaluate the effect of masking on those parameters. My oxygen saturation range dropped a couple points and didn't come back up. Meanwhile there was a sustained increase of 10 to 15 points in the pulse rate and within 15 minutes I see a rise in pulse pressure from 50 to 100 (difference between systolic and diastolic pressures). I experienced a worsening headache and nausea within minutes of masking. It took several hours for the headache and nausea to resolve. My blood pressure dropped very slowly after taking off the mask It was not back into the normal range until the next day.

I have monitored pulse and oxygen saturation at home since 2018, Readings at rest and while walking typically ran 98 to 100% prior to getting covid 19 symptoms in March 2020. Oxygen saturation dropped to 90 to 92% during the illness, and stayed below 95% for several months. For the past year my O2 sat readings are usually no higher than 97% and no lower than 94%.