Mama June reveals vision loss has caused her to miss family milestones (exclusive)

Mama June is getting candid about the impact her partial blindness has had on her life.

Despite the reality star's amazing weight loss transformation last year, June still faces a number of health problems, including impaired vision that she says has been a difficult challenge throughout her adult life.

"I will never get any vision back in the right eye," revealed June, who said she lost sight in her right eye before her original reality series, Here Comes Honey Boo Boo, ever aired. "[And] the left eye, it's no guarantee."

June and her 12-year-old daughter, Alana "Honey Boo Boo" Thompson, sat down with ET's Lauren Zima on Monday, and reflected on what June's vision problems have cost her.

"I have graduation and, like, so many things coming up and there is possibility that she won't be able to see me walk across the stage," Thompson said, admitting that she's somewhat scared of the potential for her mom to lose her sight all together.

It's a very real fear that June shares, saying that she's already missed out on some important milestones in her kids' lives, including daughter Jessica Shannon's graduation.

"When Jessica graduated college back in May, I wasn't able to see that," the 38-year-old reality star shared, getting choked up. "It's emotional for me just thinking about it."

June also revealed that one of the possibilities that upsets her the most is not being able to see her baby granddaughter, whom June's daughter Lauryn "Pumpkin" Shannon, welcomed in December.

Mama June made headlines last year when she underwent a shocking weight-loss journey that saw her drop over 300 pounds and fit into a size 4 dress as part of the docuseries Mama June: From Not to Hot.

However, in the months following her numerous medical procedures as part of the show, June has put a few pounds back on, and she's getting a lot of support from her little girl.

"It's understandable why she would gain the weight back," Thompson shared. "She's had so many surgeries in the last six months, it's totally understandable. I would gain weight if I had six surgeries in the last six months [too]."

June's battle to keep the weight off and lose what she's gained back will be the subject of the upcoming second half of season two of Mama June: From Not to Hot, which premieres June 15 at 9 p.m. ET/PT on WE tv.