I went back home for a bit to spend some long overdue R&R with friends and family. I noticed the first couple of days the phone seemed to be ringing a lot, and every time, there was a short conversation, and it was over. When my parents hung up, they would say, "Oh, so-and-so called just to say cheshm roshani that you are home." Of course! Aunts, cousins, friends calling to tell my parents:
چشم شما روشن / cheshme shoma roshan
This phrase literally means may your eyes be bright. When a traveler arrives at a friend or family's house (either after traveling a long distance or not having seen the person in a long time), friends and family call to say this. It's like saying the traveler has brought light and goodness to the house. So my relatives were telling my parents, cheshme shoma roshan, Pontia is home!
Back at work, my co-workers asked if I saw my family. I said yes, and the response was "Great! Cheshmet roshan!" So the same way that I brought light and goodness by visiting home, it was also returned to me.
If you didn't know that someone was coming and you find out randomly in conversation, you can still say it. "Oh, Pontia is visiting? I didn't know that! Cheshme shoma roshan!"
This phrase can also be used sarcastically. Say you know someone who is a model child/citizen/employee. Then as you are talking to your friend, you find out that this person has a few skeletons in the closet. You might tell your friend cheshme [maman o babash] roshan! may the eyes of his/her mother and father be bright! In this case it's expressing a sort of sarcastic shock, like uh-huh! I knew he/she wasn't all that great!
Or say someone tells you that there were 8 leftover bottles of wine from an Eid-al-Fitr (last day of Ramadan) party. Wine at a Ramadan party?? Cheshmam roshan! (This is a true story, and that was my reaction.)
You can also use it in a teasing manner. For example, your little cousin went to a club for the first time and then casually tells you about it. You can't believe your cousin is all grown up, so in a teasing way you say, You went to a club!? Cheshmam roshan! It's almost implying in a joking way that oh, you are doing naughty things, and I'm going to tell, and you will get in trouble.
August is always a travel month, so if you are seeing anyone after a long time, cheshme shoma roshan!