Men are more visually stimulated than women. Everybody knows that, right? That's why they've enjoyed pornography for centuries while women have not. Sure, women enjoy beautiful landscapes and artworks. But, when it comes to sexual images - nothing. Their ability to respond is mysteriously switched off."I think that's complete bullshit," says Erika Lust, an award-winning 37-year-old pornographer. Her company, Lust Productions, pulls in around $1-million a month from website subscriptions with a customer base that is 40% female. "Women didn't like the pornography they saw in the past," she says. "That doesn't mean we don't like any images at all."One of the world's most popular free sites, Pornhub, which is visited by 156million people every month, recently revealed that women make up a quarter of its global audience.With the internet, and particularly smartphones, the barriers to porn are gone; few were the women with the guts to buy top shelf magazines or rent X-rated films from mangy-looking sex shops. But having a personal, internet-enabled device means being able to discreetly access explicit material - and that's changed things for many women.Those aged between 18 and 24 - the generation that grew up with smartphones - represent the biggest slice (35%) of Pornhub's female audience, with those aged 25-34 not far behind. As a result, "the industry is taking women as an audience very seriously," says Sharan Street, the editor of the industry magazine Adult Video News.Five years ago, a new "romance" category was added to the AVN awards (the adult Oscars) because, Street says, "there's so much coming out in that genre. The people making these films are often women, and they're trying to reach other women."Street describes "romance" films as "little vignettes, with more context than a typical porno: he's your boss at work, or you're giving in to an extramarital affair. There's more foreplay."You'd be unlikely to use the word "romance" when describing the work of Joanna Angel or Jacky St James, two of the most successful female pornographers. (The strap-line on St James's website runs, "good girls like it bad"). But St James, half of whose subscribers are women, does adhere to some of the characteristics Street describes. "I like to have a relationship established before the sex," she tells me. "Unlike a lot of hardcore where they met five minutes ago".St James is 38. "When I was a teenager no woman even admitted to masturbating," she marvels. "But younger girls are watching a lot of porn."Most people are surprised by this - not least the many women who have logged on to explicit sites only to find nothing they liked. Claire, a 27-year-old management consultant, describes her typical experience with porn sites as going like this: "Click 'play.' No, try something else. No, try something else. Definitely no! Okay, the moment's passed.""I'm looking for a woman enjoying herself," she says. "Instead, I find films of women being called sluts, who don't look remotely turned on. I'm open to porn, like most of the women I know, but I often just find it off-putting and gross."There is a wave of content aimed at female viewers but it's still a small slice of what's out there.According to Pornhub, women are far more likely to watch lesbian than heterosexual porn. The student Amy Hart describes herself as "straight as a ruler". But, she says, "I don't want to watch a girl being aggressively f****d up the bum. Lesbian porn is less threatening: it's non-intrusive and, generally, fairly gentle." Also, "girls constantly receive oral sex in lesbian porn". Women search for cunnilingus on Pornhub 900% more than men do.The Feminist Porn Awards began two years ago to recognise explicit films that represent female sexuality more truthfully. In the organisers' view, "the answer to bad porn isn't no porn - it's to try to make better porn".In 2005, Lust began doing just that, shooting erotic films alongside her work in the mainstream film industry.Lust's films have a dreamlike quality, often with little or no dialogue but a perfectly clear sense of the situation and the dynamic between the characters. She will often sacrifice "gynaecological" shots to capture a more authentic sex scene."I show touch, intimacy, connection," Lust says. "I show the eyes. Women look for the man's expression, not just his body."..