Probably not fed them, or removed the leaves before they were finished.
This year give them a really good feed with general fertiliser and they should be back to normal next year.

Are you sure that the Hyacinth is flowering and not still emerging? Seems rather early for Midlothian. They are hardy, so unless your garden is a bog, I would leave them and do as Owdboggy has said and feed them.

Thank you to Owdboggy and Botanic for prompt replies - I do use "Miracle Grow" all over my garden but maybe I did take leaves off too soon. I will have more patience this year.

Tp be honest, this always happens with hyacinths, particularly the ones that were originally 'prepared' to grow in the house in winter. They all eventually end up looking more like bluebells than hyacinths. I guess if you make a huge effort to feed them specifically in the ground every year, and leave the leaves in situ to rot away on their own, you may get more years out of them, but they will eventually end up like you describe.

Thank you very much - I suspected this might be the case.........................I have now fed the ground around them with chicken fertiliser will monitor! So I will in future buy bulbs from garden centre and put them directly into garden and see what happens .