A common beauty item could lead to blindness, a leading doctor has warned. Dr Saurabh Sethi, a US-based doctor trained at Harvard University, warned beauty lovers about the potential dangers of eyelash glue, as he said some brands may release a dangerous chemical that can have serious health implications, and in rare cases, cause blindness.

In a video shared on Instagram, he warned that some eyelash glue releases formaldehyde, a chemical used for preserving dead bodies. He said: "Fake eyelashes are becoming increasingly popular, but the adhesive glue often contains formaldehyde, which can cause allergic reactions, thinning and permanent loss of natural eyelashes."

The doctor added: "In rare cases, it can even lead to blindness. To minimise this risk, avoid fake eyelashes or use formaldehyde-free adhesives."

Experts said that formaldehyde helps improve the shelf life and stickiness of lash glue, but at high concentrations, the chemical can trigger shortness of breath, headaches and skin irritation.

An American study from 2022 found that 75% of 20 professional products released formaldehyde, while four of 17 consumer glues also contained the chemical.

Only two consumer glues declared formaldehyde as an ingredient, according to the study.

However, according to the website Lash Base, a lash retailer, the main ingredient in all lash adhesives is cyanoacrylate, which is made from formaldehyde.

It wrote: "After cyanoacrylate is formed, the eyelash adhesive is purified through a process known as chromatography to get rid of excess reactant (formaldehyde).

"This process purifies the lash adhesive and makes it safe for client use. After this process, there are only trace amounts left."