"Most Chinese optical shop owners or customers are eager to see you are already quite a famous brand, otherwise the brand cannot attract their eyes," she says.

She hopes to overcome this and popularize her brand in China through her Shanghai training team, who she sends to train staff in optical shops that carry her designs.

"Denmark is a very small country as it only has 5 million people, and we need to go out if we want to have further development," she says.

Esto says her decision to branch out into China was inspired by Danish author Hans Christian Andersen.

"Andersen was a very open-minded person. Even in olden times he used to travel for three weeks on horseback in order to have a look at the other side of Europe."

Esto's designs are European, but she says they have been adapted for the Chinese market.

"We make the frame wider as Asian people tend to have a wider face. Also, because people in Europe have a high nose, we make the nose pad a little bit lower so as to fit an Asian face."

Esto has been surprised by the attitudes to fashion she has found in China.

"There are a lot of girls who wear glasses without lenses, just for fashion. Also, Chinese people are not afraid of colors, so while my products have entered the market, I'm so happy to see they like them."

After comfort, one of the most important factors in choosing glasses is to make sure they come up to the eyebrow, as ones that sit too low make the wearer look tired, she says. Color is also important, and choosing the right pair can depend on a person's skin.

"If a person's skin color is very yellow, then a yellow toned frame does not fit for her or him, but a cold color will be more suitable. Similarly, if a person's skin color is very red, a red toned frame will not go well with their skin color, and a warm-colored one will be more suitable."

To produce yet more styles for China's fashion-conscious crowd, Esto says she plans to work with the country's fashion designers.

liaoxue@chinadaily.com.cn