Thanks for your question on Health Care Magic.
I can understand your husband's situation and problem.
By your history and description, possibility of
sarcoidosis is more in his case.
It is
granulomatous disease affecting lungs and mediastinal
lymphnodes. It can cause ground glass appearance of lungs on
CT scan (white paint like as you mentioned).
It also causes breathlessness on exertion.
And hence PFT (Pulmonary Function Test) and blood reports like
complete blood count, serum calcium level, ACE level etc are needed.
The most confirmatory test is lung biopsy.
Sarcoidosis can also affect retina and hence eyesight problem he is having can also be due to sarcoidosis.
So get done PFT and blood reports, follow your doctor 's advice and if needed also get done lung biopsy.
Hope I have solved your query.
Wish you good health. Thanks.