WFTC medical expenses

[trulyscrumptious43]

I am self employed and get WFTC.
Doing my accounts, I'm wondering if physio/oesteo treatment for a back problem (my job entails physical labour) is allowable as a business expense or similar?
Along the same lines, would laser eye treatment also be included in my business expenses - or even capital investment!

My feeling would be that, since employer-funded private health insurance is taxed as a perk, other forms of privately funded medical treatment would be treated the same way.