found on B71, provides Damage Resistance for the eyes which is switchable.
DR does not normally benefit the eyes without Force Field enhancement.
DR, Limited is a discount of -10% per -1 to hit, so eyes at -9 to hit would be -90%
Switchable is +10% so this is basically like DR -80% with the special benefit of not having to pay for a Force Field.
also has a benefit to HT rolls against eye damage.