Staff at Children’s University Hospital in Dublin saw six cases in six months in children aged 18 months to three.
Each had suffered eye damage after they squeezed a capsule, making it burst.
Doctors called for stronger warnings on packets, but manufacturers said there were clear warnings that the products should be kept away from children.
They also suggested that manufacturers should modify the packaging to make it child-proof.
The capsules of concentrated liquid detergent are usually round or square and designed to dissolve in the wash, releasing their contents.
“However, they are of just the right size and consistency for kids to be interested in to squeeze,” said Dr Noel Horgan, one of the consultants who wrote the Lancet letter.
“We want to raise people’s awareness of the possible danger. If they are in any way wet they burst and splash,” he explained.
All of the six children that he and his colleagues treated had suffered damage to the cells lining the cornea, the “window” covering the front of the eye.
Four had also sustained significant injuries to the conjunctiva, the thin transparent layer of tissue that surrounds the eye.
The children were admitted to hospital and kept in for two to five days.
Their injuries eventually healed, but Dr Horgan said they might still be at risk of longer-term problems.
He said the fluid, which is a strong alkali, could potentially damage cells that have the job of replacing older cells in the eye.
“Even though their corneas look healthy now, there can be compromise of these cells and some time in the future, these patients could be at greater risk of running into problems.”
He said the injuries might have been more serious if water had not been promptly splashed over their eyes.
‘No lasting damage’
The washing products do carry a label stating that they should be kept out of the reach of children.
Dr Horgan said: “We propose that the warning label should be more obvious.”
He said he had written to manufacturer Procter & Gamble.
In a statement, Procter & Gamble said: “Liquid Detergent Tablets have been on the market since Spring 2001.
“Like all laundry and cleaning products, they contain surfactant that under accidental exposure can cause irritation and discomfort to the eye; which is the kind of conjunctival and, in some cases, superficial corneal effects described by the authors.
“Like other laundry products they should be kept away from children, and in the event of such accidental exposure the eye should be promptly rinsed thoroughly with plenty of water and medical advice obtained. This is clearly communicated on the pack.”
It said that safety evaluations had concluded that accidental exposure of the eye caused no lasting damage.
It added that child-proof containers caused “a significant proportion of the population very real difficulties and should only be applied when necessary.”
A spokesman from the Child Accident Prevention Trust said: “If it is possible to reformulate the product so that it is not harmful, that would be the ideal.
“Failing that, we would be supportive for improving the storage instructions and looking into the issue of putting the product into child-proof containers.”