Sharon Stone on How There Being Only 'Room for One' Type of Woman Changed Her Self-Image (Exclusive)

Sharon Stone is bucking gendered style stereotypes.

In an exclusive chat with PEOPLE surrounding her partnership with LensCrafters for the optical brand's 40th anniversary, the 65-year-old actress discusses anxiety in relation to the pressure to fit certain beauty standards — namely, feeling less of a "compulsion" to cut her hair just so, and instead let it grow out and do what it will.

"I cut my own hair forever and then once I started painting, I lost that. I think it was that perpetual anxiety," Stone says. "That perpetual feeling of rejection that society gives us with the way that women are treated: that there's only really room for one."

The Basic Instinct star gives an example of hurtful words like, " 'You're too tall, too short, too fat, too thin, too blonde, too brown, too white, too dark and too stupid to understand anything.' "

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human-interest stories.

For Stone, that kind of language "isolates women one from the other and keeps us from knowing each other, acknowledging each other, being friends with each other."

"That whole thing really got up my ass and I think it became, frankly, a compulsive obsessive anxiety illness with me, and I noticed that I had quite a few little fetishes because of it," she says. "And one of them was compulsively cutting off my hair whenever all this was happening to me."

But, Stone adds, the "constant rejection that women feel" is something that came to a halt for her when she started painting, "because I was able to accept not only me, but reality — the reality of nature and that ability to see myself and everyone else."

Painting, the Oscar nominee tells PEOPLE, "has been the biggest thing I've ever done for myself, where I just do it for me" — and she says she can spend up to "17 hours at a time" in her studio.

"It's given me back my center, my sense of perspective, my soul, my dignity, which I think was basically in shreds," Stone says. "It gave me back my humanity ... my ability not only to just see others but to really investigate others, because I'm looking at everybody now like they're a painting."

Stone is stoked to be part of LensCrafters' 40th-anniversary campaign, not only as a fan of the brand's function but its fashion-forward aspects as well.

"For anybody who has real eye sensitivity or has headaches ... it really helps to have these tinted colors, and there's a myriad of them," she says. "You can get them any way you want, and they can ombre them down. Sometimes I get a color here and less color at the bottom where I have a bifocal."

"It's just fabulous," the Casino actress continues. "I'm a glasses person. I like to have them to go with all the different stuff that I wear. I like to have night glasses and day glasses and sport glasses, and I also even have a very specific pair of glasses that I paint in."

For Stone, "comfort is really key" when it comes to her style choices in general — and she tells PEOPLE her eyewear is no different.

"It's form and function," she says. "I can't stand to wear clothes that are uncomfortable because I don't think you're beautiful when you're uncomfortable. I think you're just miserable, and I'm at the point now where I think high heels have run their course. I think we need shoes that don't make you miserable, where your feet aren't killing you the whole time. What's the point?"