... and the older my eyes get, the worse the problem becomes.

The various language variants of WST_ are _less_nasty_ than some (for 'doze), though they still leave much to be desired. Even better, IMO, is the proggy.... fontset, with many plusses, including slashed or dotted zeroes, readily distinguishable { and ( (with bold variants, which help me lot), etc.

Had semi-seriously considered building my own, with special attention to diffs between curly and paren, semi and colon, etc...
but good sense (as in limited graphic talents and knowledge so eone else has already done it well) has so far prevailed.