ll. 7-8. Though he had wont to search with glazed eyes,
As though he came to kill a Cockatrice,
i.e. 'with staring eyes'. I take 'glazed' to be the past participle of the verb 'glaze', 'to stare':
I met a lion
Who glaz'd upon me, and went surly by,
Without annoying me. Shakespeare, Jul. Caes. I. iii. 20-2.
The past participle is thus used by Shakespeare in: 'With time's deformed hand' (Com. of Err. V. i. 298), i.e. 'deforming hand'; 'deserved children' (Cor. III. i. 292), i.e. 'deserving'. See Franz, Shakespeare-Grammatik, § 661.
The Cockatrice or Basilisk killed by a glance of its eye:
Here with a cockatrice dead-killing eye
He rouseth up himself, and makes a pause.