Orthoptic or similar treatment prescribed by a practitioner (Routine Ophthalmic Care - i.e. Sight Testing, Spectacles, Contact Lenses, does NOT qualify for tax relief);
I have quoted this from the revenue website. I would suggest that if a practitioner recommends that it is replaced that it may be allowable. You can get an opinion on this by the Revenue either by registering on line with the PAYE service (unless you are self assessed) or by writing or visiting your local tax office.
My feeling on this would be that if it Is necessary it would be reclaimable.