It happened in a flash.

John “Jay” Loos was watching a Cubs game at Wrigley Field from his seats not far from the visitors’ dugout.

He heard the crack of a bat. Excruciating pain followed. A line drive foul ball hit him in the left eye.

“I never really saw it … it just hit me and I wasn’t unconscious so I knew I must have been hit by a ball,” Loos, 60, of Schaumburg, said Monday — three days after filing a lawsuit against the Cubs and Major League Baseball.

Bleeding from the eye, Loos fell onto his 30-year-old son, Adam, who was seated next to him.

The game was Aug. 29 against the Pittsburgh Pirates.

He was placed on a stretcher and carried to an ambulance. Doctors told him the impact broke five bones and tore a hole in a sinus.

Six weeks have passed. He has no vision in his left eye.

Guy took it right to the dome on that foul ball in the cubs game.. #Ouch #Cubs @BarstoolBigCat pic.twitter.com/ScEkQattbQ — John Lloyd (@John_K_Lloyd) August 30, 2017

After three surgeries — and with two more on the horizon — Loos has come to the realization that doctors might have to remove the eye and replace it with a prosthetic.

Loos played baseball in high school and said he knows there are “hot zones” in the stands where foul balls land, but was astonished all the same.

“I had no idea that you were subjected to such missiles and the rate of speed that a ball can come into the stands.”

Loos said he was not on his cellphone at the time of the accident.

He spoke to reporters Monday at a news conference held at his attorney’s downtown office.

Describing the vantage point from seats near home plate and the dugouts, Loos said: “You can’t tell when the ball is contacted, you can’t tell where the ball is going, you can’t tell the rate of speed it’s going until it’s on top of you.”

“I don’t want anybody to have to go through what I’ve been going through,” Loos said Monday, urging the Cubs and all teams in the league to extend protective netting the length of the dugouts on each side of the field.

Such netting, which Loos insists would not distort views of the field, would have stopped the ball that hit him, Loos and his attorney, Colin Dunn, insisted.

Loos was sitting in Section 135, Row 11, Seat 107 — roughly a third of the way from the infield dirt to the right-field foul pole. Chad Kuhl, a pitcher for the Pirates, was the batter.

Dunn said he’s been in touch with Cubs attorneys. “I do believe that they want to do the right thing for Jay. They told us that they’re willing to talk to us and so I take that at good faith. I do think they care about their fans.”

Dunn, who did not specify an amount he’s seeking in damages, said he’s yet to speak with a representative from the League.

The MLB players union tried to include the safety measure in past contract negotiations, said Dunn, who added that such netting is standard in Japan.

The lawsuit, filed Friday in Cook County Circuit Court, represents one of the latest in a series of similar incidents at ballparks around the country.

On Sept. 20 — less than a month after Loos was hit in Chicago — a 105 mph foul ball off the bat of Todd Frazier struck a 2-year-old girl in the face at Yankee Stadium in New York.

The toddler, sitting in her grandfather’s lap, suffered a broken nose and other facial fractures that caused her eyes to swell shut, her father told the New York Times.

A few days after the incident in New York, Cubs President of Business Operations Crane Kenney said on “The Bernstein and Goff Show” on 670 AM The Score that the team would extend the safety netting at Wrigley by at least 30 feet — up to the beginning of the dugouts — for the 2018 season.

And while other teams have announced similar plans to increase netting along the first and third base lines, the MLB hasn’t mandated extended nets despite similar incidents in previous years. In 2015, the league recommended, but did not require that nets reach the start of the dugouts,

with 10 of 30 teams taking the advice.

The newest injuries, however, have convinced league executives to revisit the issue in the offseason, with critics suggesting mandatory nets to the end of dugouts.

In September, MLB Commissioner Rob Manfred said the fan injuries were “extremely upsetting.”

“Over the past few seasons MLB has worked with our clubs to expand the amount of netting in our ballparks,” Manfred said in a statement. “In light of yesterday’s event, we will redouble our efforts on this important issue.”

Ald. Ed Burke (14th) has pushed both Chicago teams to add protective measures, even going as far as proposing an ordinance to force the Cubs and White Sox to add more netting.

“This has become a safety issue around the nation as more and more fans have become aware of the dangers associated with viewing major league baseball games,” Burke told the Sun-Times a few days after Kenney’s radio interview. Burke wants an ordinance in place by the next Chicago City Council meeting on Wednesday.

In New York, City Councilman Rafael Espinal introduced similar legislation in May that would make netting from the backstop to the foul poles mandatory in all New York ballparks with more than 5,000 seats.

Sen. Dick Durbin (D-Ill.) also joined the calls for increased safety as he urged Manfred to extend the netting at all 30 MLB parks.

“The solution is clear: extend the nets protecting the fans,” he said in a letter to the commissioner. “Ten teams have already taken this important step. But, it is not consistent throughout MLB stadiums. For the good of the sport and the safety of your fans: extend the nets.”

Loos said Monday that if he had the opportunity to sit in the same part of the ballpark again for a post-season game he’d pass.