‘And Laban had two daughters, the name of the elder was Leah and the name of the younger was Rachel. And Leah's eyes were tender, but Rachel was beautiful and well-favoured.'
The word for ‘tender' can mean soft, weak, delicate. This may indicate some weakness in the eye or it may simply mean timid or gentle-eyed (compare Deuteronomy 28:56). The point was that while Leah was not unattractive she paled in comparison with Rachel.