eye contact in reflections

a list of questions to bother my medical-student brother with:

1. What are the neurological impulses that signify "the meeting of eyes"?

a. "Eye contact" surely cannot be quantified by a ray of light reflecting off the other party's irises and bouncing into our own optical nerve, right? Otherwise, "eye contact" would be considered valid in scenarios with one-way glass or sunglasses.

2. There must be some sort of trigger mechanism that registers the realization: "ah that person has met my eyes".

a.To elaborate, there is a difference between looking at someone's eyes, and meeting someone's eyes. For example, if an optometrist is examining my eyes through an optical instrument, I can sense that their eyes are focused on my eyes. But since I cannot see the optometrist's own eyes, the eye connection is unidirectional and hence the act of "eye contact" did not occur.

3. To describe my understanding of "eye contact" as succinctly as possible:

a. Both parties focus their line of sight on each other's eyes.

b. There is a mutual acknowledgement that the other party knows they are being watched as well.

4. Eye contact is an essential tool of nonverbal communication among most creatures and I've honestly been pondering this question for a few years now, ever since I've developed the habit of observing strangers through their reflections on the subway windows. 

a. Empirically, I have seen (somewhat awkwardly) that eye contact can occur through a third-party medium such as a window reflection. Somehow, along the rays of light from my eyes to the glass to the stranger's eyes, there is the jolt: "Aha. I've been caught spying".

sanguine

Sanguine is an interesting word. I am no etymologist, but for some reason (most likely due to a book I have read in the past) I associate "sanguine" with blood. A quick search on the internet confirms that the second listed definition of the word is "blood red", and further down the list of related terms are "bloodthirsty" and "bloodshed". Synonyms for sanguine include "murderous". Sangrias are often red as well, I believe. 

Sanguine is derived from the Latin word "sanguis" for blood. So I do get quite confused when the top-ranked definition for sanguine is "marked by eager hopefulness, confidently optimistic". Does the optimism come from a murderous intent to smile in spite of difficulty? Does a rush of blood promote the flight-or-fight bodily response that affords an eager hopefulness for survival? There is most likely a logical explanation for the discrepancy in meaning behind this word (perhaps it is just anachronistic terminology), but I will always wonder for a moment whether I should smile at or flee from a person feeling sanguine. 

when you have many things to do but no willpower to get started, you make a bucket list of transportation systems to visit

 1. Hong Kong MTR

2. Eurostar 

3. Shinkansen

4. Moscow metro (look at this map!)

5. Stockholm Metro

I've been lately thinking about ways to become more environmentally conscious beyond the usual sorting of recyclables and compost. Driving less and opting for public transit (if the area permits) would be ideal, which leads me to search for places with good urban planning.