Xavier Lim and Jae An are five-year-old boys who see the world through glasses - not for myopia but astigmatism.
They are among a growing group of pre-school children with problems such as myopia or astigmatism, which is blurred vision due to uneven curvature of the eyeball.
About 16 per cent of kindergarten children are short-sighted, according to the latest Health Promotion Board (HPB) figures from 2011, up from 7 per cent in 2009.
There is no separate figure for astigmatism, which can occur together with myopia, but the Singapore National Eye Centre (SNEC) said it is "quite common" among the pre-schoolers it sees.
Dr Cheryl Ngo from National University Hospital noted a 15 per cent rise in pre-school referrals to her clinic in the past few years.
Vision problems among young kids are being detected at annual screenings held by HPB at childcare centres and kindergartens.
About 25 per cent of the 75,000 K1 and K2 children screened each year are referred for further assessment when they fail the test, said HPB, which started such screenings in 2002 to prevent and reduce the early onset of myopia. About 65 per cent of 12-year-olds are myopic.
Jae's mother, Mrs Lynn An, 34, said she noticed that he would rub his eyes and see things up close. He was diagnosed with astigmatism after failing the kindergarten eye test in June.
"I felt so sad for him that he has to start wearing glasses so early in life, but I got over it quite quickly because I know he needs them," said the finance manager, who is myopic herself.
In Singapore, astigmatism is the most common cause of amblyopia, or "lazy eye", where the brain is so used to seeing blurred images in the affected eye that it cannot adjust to seeing clearly even when given the best glasses.
"If it is not treated early, it may lead to permanent poor vision in the affected eye," said SNEC senior consultant ophthalmologist Audrey Chia.
Dr Ngo cited a case of a boy who could not see clearly beyond his outstretched fingers - he had 500-degree astigmatism and 700-degree myopia in his right eye. But his parents did not notice this until he was screened in K1, as "he could still see with his good eye", said Dr Ngo.
Most children are born with some degree of astigmatism. But only moderate-to-high levels of over 150 degrees need correction, and this affects about 8 per cent of the population. Astigmatism is best treated before a child's visual system is fully developed by age seven or eight, say doctors.
Mrs An said Jae has one "lazy eye" but his condition has improved since he started wearing his blue-and-red frame glasses. "He loves wearing them and says they are his Spiderman glasses."
Xavier got his glasses in August but wears them only to kindergarten or when doing his homework.
"He keeps saying he can see," said his mother, 37-year-old office manager Rachel Soh. "But we've been encouraging him to wear his glasses every day."
Children can cope with visual problems by tilting their head and squinting to see better, said senior consultant optometrist Yap Tiong Peng of optical chain Igard Group.
Mr Yap, who is studying how the brainwaves of astigmatic children respond to wearing glasses, said the brain may take time to "start appreciating sharp vision".
Some parents blame the use of mobile devices for vision problems. While this could be true for myopia, it is not so for astigmatism, which usually stays stable throughout life, say doctors. But it can worsen due to droopy eyelid or cornea injury.
But some parents, like Mrs An, are not taking any chances.
She said of Jae: "He seldom uses the iPad as I don't encourage it. When he's watching TV, I'd remind him to rest his eyes and stare at green (things)."