In my slightly covid unrelated case, intracranial tension changes cause very subtle sharpness/clearness vision changes. So look out for these things, there might be more problems associated with it! Like IIH, CSF leaks or venous stenosis. It can cause a wide variety of seemingly random neurological pressure changes. Beware of substances affecting it like caffeine, weed, fat-soluble thiamine and Lithium. These can reduce or induce serious problems especially if the intracranial pressure is unstable. And while these might possibly be useful, be aware it is poorly understood overall and can cause damage.