Per the last entry. Notice the special attention to 'eyes' in the canon? All the psyche information and power transferred by such? Zelazny often makes a point of passing information about eye color, looks, empathy, mood and guesses by eye contact.
It is in Eric's eyes that Corwin first learns that his brother may have something to fear from Corwin's blade.
A cultural oath in Amber is, "damn his eyes!"
When Corwin decides to put off a Trump call, he actually closes his eyes as part of his defense.
Twice Corwin drops or averts his eyes to defend against Strygalldwir. Then: "As my death grip tightened, its eyes sought mine, and this time I did not avoid them. There came a tiny shock at the base of my brain, as we both knew that we knew."
A bit later, eye contact in a fight with Strygalldwir's Lord passes Corwin's identity again.
And of course, the Jewel of Judgment is entered also by eyeing the interior.
IMC, eye contact is not the most efficient way to transmit psyche energy. The most efficient way is magic and/or Trump that establishes arcane supported contagion. The range of this is dependant on the skill of the transmitter and cooperation of the receiver. At one rank down is physical touch which is not dependant on skill but is altered by fabric or physical coatings and arcane protections. At two ranks down is eye to eye contact. At three ranks down is eye to nerve contact.
Yes, that last is seldom discussed and not included in the Amber DRPG rules. However, it is theoretically possible for any large expanse of nerves to carry psyche energy. So tales of dancers who mesmerize spectators are quite true. Such dancers usually remove as much clothing as possible in order to send as strong a signal to the viewing eye.
There are a few varieties of beings that are more dangerous naked than armed with steel.