At age 8, Esubalew “Ethan” Johnston was blinded by criminals who forced him to beg in the streets of Ethiopia, handing over his profits as he pressed strangers for a morsel of food.

Twenty years later, Johnston is living in the United States and enjoying life as a lightning-fast third baseman in the national amateur baseball league for the blind.

“For the first two or three years, I was so amped up, I’d end up striking out [by swinging too hard],” Johnston told The Post. “Or I’d want the ball to make an out for my team, but sometimes I overran it and the other team scored.”

In time, Johnston became one of the league’s best players, earning Defensive MVP honors in 2010.

His incredible rise, among many other uplifting tales, is detailed in the new book “Beep: Inside the Unseen World of Baseball for the Blind” (Swallow Press) by David Wanczyk, out now.

The National Beep Baseball Association officially began in 1976. Using a baseball that beeps so blind players can locate it, each team fields six blind defensive players and a sighted pitcher who throws to his own teammates from just over 20 feet away. First and third base are four-foot-high pylons (there is no second base), one of which beeps when a ball is hit. The player must run to that base before the defense, which is searching for the beeping ball, safely fields it. (Players are hit by balls all the time, but shrug it off just as they do in the majors.)

Johnston, now around 28 (he doesn’t know his birthdate), knew nothing about baseball growing up with full eyesight in Gojam, a small town in Ethiopia, where he lived in a grass hut with his family.

“The walls were made out of logs and mud,” Johnston said. “Everybody slept on the floor, on a cow mat, in the same room with our chickens.”

Then two men from Addis Ababa appeared and told his mother they could take Johnston away to be educated, and bring him home once a month. His mother, wanting the best for her son, agreed.

But after a six-hour trip to the city on a donkey, the men attacked Johnston, holding him down and pouring chemicals into his eyes.

There was no school. Their intention all along had been to blind him and force him to beg in the streets, since blind beggars earn more.

Johnston did this for more than two years, giving his money to his handlers and hoping strangers would feed him. “They never fed me, and never gave me one penny of what I earned,” Johnston said of his captors. “Sometimes I got beaten, and they’d say, ‘Tomorrow you need to make more money.’ I thought I was going to die begging.”

After several years, he was rescued by a couple overseeing a school for the blind in the city, who frightened his handlers into handing him over. Thanks to their help, Johnston was sent to America, where he was adopted by a family in Ashland, Mo.

Around 2005, while in high school, he began attending the Colorado Center for the Blind, which teaches its students how to handle everyday tasks while pursuing larger goals. There, he met Demetrius Morrow, a player on the Colorado Storm, who introduced him to beep baseball and arranged for him to try out for the team.

Johnston, who has had 49 eye surgeries and can now see light and colors, showed up in basketball shorts and a Kobe Bryant jersey.

“I just went at it,” he says. “Playing defense sucked, because you have to dive on the ground, and my whole body was exposed.”

But Johnston, who ran track and field in high school, impressed everyone with his speed, and fell in love with the opportunity to excel. He was offered a spot on the team, and has been a member of the Colorado Storm since 2008, wearing an eye mask to prevent him from cheating, given that he has some ability to see.

The beep baseball league currently has 33 teams, a number that can fluctuate depending on their ability to secure funding. The sport’s annual season is basically all playoffs — teams play elimination rounds every August, in a different host city every year, until a champion is determined. In the 10 years Johnston has been on the Storm, they have never won the championship.

Johnston, who has been married for six years and works as a claims processor for the Social Security Administration, feels a pressing desire to finally win a championship for Colorado, which has finished third in the league three out of the past four years.

“I want to win it for my coaches and volunteers, especially those that put in their money, their time, their sweat and blood into this team,” he said. “They deserve it more than the players.”

For Johnston, it would also be the pinnacle to what has been an astounding journey from a hut to a criminal’s lair to an innovative sport that is changing lives for the better.

“Usually when blind people are in physical-education classes, their coaches tell them, ‘Just sit on the sideline and watch,’ ” Johnston said. “Beep baseball gives you the opportunity to compete to the highest level with other great blind athletes, and with freedom. You don’t have to worry about running into a tree.”