("Can you see him?") Jill stared straight into the customer's eyes and gave him a warm smile... not alone to increase his interest in her but also to let Mike use her eyes, if possible.  As her grokking of Martian thought had increased and as they had grown steadily closer in other ways they had begun to be able to use this common Martian convenience.  Not fully as yet, but with increasing ease - Jill had no control over it; Mike could see through her eyes simply by calling to her, she could see through his only if he gave it his attention.