Jose Mourinho was left fuming after Raheem Sterling escaped a red card for a reckless tackle on Dele Alli during Tottenham's clash with Manchester City.
Sterling trampled on Alli's ankle midway through the first half, leaving the England international writhing in agony on the floor.
Sterling did attempt to apologise to Alli, who hobbled off the pitch before returning to the action after several minutes of treatment from Spurs' medical team.
Sterling was given a yellow card but a VAR review of the tackle deemed that it wasn't worthy of a red card - though Mourinho disagreed.
The Portuguese watched a replay of the incident on a touchline monitor and then made a gesture to the fourth official suggesting that he should start wearing glasses.
Mourinho then continued to demonstrate his disgust at the decision as play continued, while his assistant, Joao Sacramento appeared equally unhappy.
The incident was the highlight of a scrappy opening half an hour but appeared to spark the game into life at the end of the first half.
Manchester City were awarded a penalty after Sergio Aguero was brought down by Serge Aurier in the penalty area.
But Ilkay Gundogan's effort was saved by Hugo Lloris, who then dived to stop Sterling from reaching the rebound, with the winger falling to the ground.
City's appeals for a second penalty went to a VAR review, but officials ruled that Lloris hadn't made contact with the winger's outstretched leg.
Mourinho was irate again on the touchline, calling for Sterling to be given a second yellow card and sent off but Mike Dean opted not to punish him.