Kittens are born with their eyes sealed completely shut — their world is all darkness and warmth for the first week of their lives.

When a kitten is born, its eyelids are fused together. They cannot open them, no matter how hard they try. For the first seven to ten days, their whole world is their mother's warmth, her heartbeat, her smell, the soft sound of her purring.

Around ten days, the eyes begin to open — slowly, just a tiny crack at first. The world must seem very bright and very big. And the colour? Kittens' eyes are always blue to begin with. The true colour — green, gold, amber — comes later, as they grow.

Holding a very young kitten is holding something that still lives in a world of feeling and sound, not sight. Their whiskers help them feel the world. Their nose leads them to milk. They are soft and small and finding their way, just like all babies do.

Look into your baby's eyes today. Notice the colour. Did you know eye colour can keep changing for months? Some babies' eyes shift from blue to brown slowly, like kittens, as the months go by.