Scott Disick: Image - Bettina Cirone

Ophthalmologists have aired doubts about whether an eye colour changing balm promoted by Scott Disick on his Instagram could actually work, Buzzfeed reports.

Disick - whose main claim to fame is having fathered three children with Kourtney Kardashian - reportedly urged followers to buy the iColour product from Amazon indicating he was paid for the post promoting the product which claimed it would "naturally" change eye colour over time.

On its Amazon listing, IColour says its NZ$50-a-month drops inhibit the activation of key enzymes to block the production of melanin in the eyes. However, eye experts told Buzzfeed the drops were unlikely to work.

American Academy of Ophthalmology spokesperson, Minnesota ophthalmologist Dr Andrea Tooley explained genes determined how much melanin was in the cells in the iris, which in turn dictated eye colour. She said eyes with a lot of melanin would be dark brown while those with very little would be blue, and “everything else is somewhere on a scale between the two extremes.”

Some diseases, she admitted, could change eye colour, but "those are all conditions that you don’t want to have."

Dr Guillermo Rocha, an ophthalmologist and past president of the Canadian Ophthalmological Society, told Buzzfeed he agreed. He said that while some glaucoma medicines had been known to darken eyes, there was nothing that worked the other way. "Nothing that can be topically applied will produce an iris that will go from brown to light blue or blue-colored," he said, adding that the claim from iColour is "I think a bit of stretch." "In general, nothing is going to make your eye turn from brown to blue," agreed Dr Tooley.

Dr Rocha also noted the iColour balm listed n-acetyl-glucosamine as an ingredient, saying it is used to treat hyperpigmentation of the skin but there wasn’t any research regarding its use on eyes.

And, said Buzzfeed, because the product wasn’t FDA approved or tested in terms of its ability to change eye colour, there was no way to know if it worked, or even what was really in it, adding Tooley had warned that putting products with uncertain ingredients in or around eyes was a good recipe for an allergic reaction or infection.

"I'm not sure how this is applied, and whether or not it would be safe, simply because there is no formal trial," agreed Dr Rocha.

Neither Disick nor iColour had responded to requests for comment from BuzzFeed.

"I think the best thing that people can do to care for their eye is love the natural color of their eye that's unique to them," said Dr Tooley.