The mesmerising close-up shots show the remarkable ocular variety the creatures have developed through millions of years of evolution. Professional wildlife photographer Daniel Heuclin travelled the world to capture the images of various tropical frogs and lizards peering straight into the lens.

Daniel Heuclin's favourite picture: 'The texture and palette of colours in such a small space is astonishing,' he said of this picture of the eye of a Panther chameleon pictured in the wild in Madagascar

Seething? A Madagascan tomato frog, named for their bright red colour, appears to peer down his nose in anger at something that is out of shot

Pensive: A Cuban tree frog narrows his pupils and stares into the distance as if deep in thought

Feline: The vertical slits of this Philippine monarch gecko's eyes are reminiscent of those on a cat

Windows to the soul: A slender-legged treefrog poses patiently for his picture He was struck by the differences he found - from the bright red iris of a Cuban tree frog to the exquisite mosaic pattern of a chameleon's eye. 'I was enchanted by the strange beauty of these interesting creature's striking eyes,' said the 65-year-old Frenchman. 'It took me a few minutes to take the photographs, but they will be extraordinarily different forever. 'My favourite image is of the chameleon's eye - the texture and palette of colours in such a small space is astonishing. 'Mr Heuclin, from Vaux en Couhe, France, snapped the tomato frog and chameleon in Madagascar. The Tokay gecko was photographed on Panay island, in the Phillipines, and the Monarch gecko in Luzon, Phillipines. The slender-legged tree frog was captured in French Guiana and the Cuban tree frog in Everglades Nal park. The Cape verde gecko and the green tree frog were observed in captivity. Mr Heuclin specialises in photographing reptiles, amphibians and rare species.

Been burning the midnight oil? The red-eyed treefrog has a glazed, determined expression

Dilated: This Tokay gecko was pictured in the Philippines

Unnerving: The contracted pupils of this giant Cape Verde gecko
make it seem like a creature from another world