A company accused of misleading consumers over claims its eye drops can cure cataracts has been ordered to complete a clinical trial to prove the product's effectiveness.

Zhejiang Shapuaisi Pharmaceutical Co, the manufacturer of Shapuaisi eye drops, a well-known brand in China, may also have to pull advertisements on TV and other media that promote the health benefits.

"Due to doubts raised by some doctors about the efficiency of Shapuaisi, ... the company should start a clinical trial as soon as possible and report the result within three years," the China Food and Drug Administration said on Wednesday.

"Misleading and ambiguous advertising should be avoided," the authority added.

The move comes after an article published on a public WeChat account operated by Hanzhou Lianke Meixun Biological and Medical Co, which cast doubt on the product's efficacy, went viral on Sunday.

Shapuaisi－a phonetic translation of "sharp eyes"－includes celebrity endorsements in some of its advertisements, which claim that its eye drops can prevent and treat cataracts.

"Surgery is the best way to cure cataracts. There is no medicine that can prevent or cure them," according to the article, which cited a report on Blindness Prevention and Treatment, a website affiliated with the National Health and Family Planning Commission.

The article also included the opinions of several Chinese doctors, including Cui Hongping, director of ophthalmology at Shanghai Dongfang Hospital of Tongji University.

Cui was quoted as saying the company had made use of people's fear of cataract surgery by misleading them to believe that the disease can be cured without surgery.

Cataract patients are mainly elderly people, who may lose their sight if the condition is left untreated, the article said. The company responded in an announcement on Monday, saying their products are safe and effective, and help to protect vision.

"Foreign research has proved the bendazac lysine in our eye drops to be effective in treating early stage senile cataracts," the company said without citing a source. However, in its ads, the words "early stage" are made so small that they are not easy to notice.

From January to September, the company said it spent 223.9 million yuan ($33.8 million) on advertising－accounting for 31.8 percent of its revenue－while its expenses for research and development only accounted for 2.16 percent.

Spending on advertising accounted for 27.1 percent of its revenue in 2014, 26.1 percent in 2015 and 26.8 percent last year.

In a statement, the company said it needed to increase publicity of the brand through advertising due to a limited number of product types compared with other pharmaceutical companies.