How to know (without a thermometer) whether an egg is cooked when we put a lid on the top of it? Last time I tried to cook sunny side up eggs on a metal skillet. I put butter on the skillet, allowed it to heat and then I cracked two eggs on it. Immediately I placed a glass lid with a hole on the eggs.

I found that the eggs did NOT turn "brown" from below (I kept on checking them periodically by lifting them up by a spoon).
After waiting for quite some time I saw the egg yolk wearing a white layer on them (from the top). I turned off the gas, and to my horror those were the most "hard" eggs I had ever eaten.

Without a thermometer what is the way to know that the "time's up"!

P.S. I DO want the salmonella to be killed.
Watch the area around the yolk for it to become translucent. Jiggle the pan a little to see if it's cooked.