When the first sign came Sam didn't recognise it.
Dean rubbing his tired eyes in the evenings, working the tips of his fingers into his eye sockets. Relishing the pressure and the relief of massaging away the fluid that collected in the little bags underneath them. By nine o'clock most evenings his eyes looked bruised and slightly puffy. Sam mentioned it once and dared to suggest cucumber slices to relieve them, to which Dean had said "And exactly how gay are you Samantha?", and it was never mentioned again.
When the second sign came Sam was suspicious.
Dean had gone from rubbing at his eyes, to working away at his temples, using the flat of his palms to try and bring some kind of comfort.
"Another headache?" Sam asked.
"Another headache." Dean confirmed in a grumble.
"That's the fourth one this week."
"Probably a tumour."
"That's not funny."
"Shut up bitch and find me some Tylenol."
And when the final sign came, Sam's suspicions were confirmed.
"Look at this." Sam said and thrust their father's open journal across the table to Dean.
Dean set his beer down and picked up the book, and squinted. He moved the book away from his face, until it was an arm's length away and then pulled it back in close.
"Dean?"
"What?" Dean screwed up his eyes in concentration.
"Are you having trouble reading that?"
"Dude, stop talking crazy and go and get me another beer."
Sam stood up reluctantly and manoeuvred through the throng of people to get to the bar. As he did so he noticed, out of the corner of his eye, Dean reach into the inside pocket of his leather jacket that was slung on the back of his chair, and pull something out. Sam grinned to himself and turned away, waving a twenty at the busy bartender.
Sam slammed the bottles down on the table so hard that froth foamed from their tops and made little beery puddles at their bases. Dean jerked up suddenly and snatched the glasses from his face and tried to hide them under the table.
"Whatcha got there?"
Dean looked uncomfortable. "Nothing." He lied. He pointed at the open journal "Think this is what we're looking for then?" he asked, trying to change the subject.
"Show me." Sam insisted.
Dean frowned "Show you what you little pervert?"
Sam laughed "Dude, I know you're wearing glasses."
"Wrong."
"They're in your hand under the table."
"I'm not wearing them though."
"Ha ha. Come on, I wanna see."
"No."
"Dean, there's nothing shameful about wearing glasses."
"I don't need to wear glasses." He paused "I just need a little assistance with, you know, reading sometimes."
"What about driving?"
"Maybe."
"Seeing in general then really."
"It's no big deal."
"I know, so show me." Sam crossed his arms and put on his best resolve face.
Dean sighed heavily and withdrew his hand from under the table and opened the glasses and propped the small lightweight gold frames on his nose. "There."
"Nothing wrong with that. They make you look…"Sam groped around for the word.
"Handsome?" Dean offered
"Not particularly."
"Intelligent?"
"Hardly."
Sam clicked his fingers, "They make you look British."
Dean took them off again.
"Put them back on, I'm just kidding."
His brother frowned at him but he put the glasses back on and turned his gaze back to the book.
"Speccy." Said Sam quietly.
Dean looked up "What did you just call me?"
"Speccy four-eyes."
"Dude I am so gonna kick your skinny ass."
"Mind you don't break your glasses."