An active component of the contraceptive “mini-pill” can reverse a genetic eye condition that normally leads to blindness, research has shown.

The study, conducted in mice modelling the human disease retinitis pigmentosa, showed that the drug norgestrel could “rescue” light-detecting retinal cells.

The synthetic progestin hormone allowed mice which should have gone blind to retain their sight.

A new study is now planned for next year to see if humans experience the same protective effects.

The research is published in The Journal of Neurochemistry.

Tom Cotter, professor, who led the Irish Republic team from University College Cork, said: “The drug seems to work by stimulating the production of a protein survival factor called FGF from neighbouring cells in the eye and this helps the light-detecting cells to survive and the animals to see.

“FGF binds to the surface of the light-detecting cells and sends a signal to their DNA to up-regulate strong cells’ survival pathways.

“In other words, it ‘beefs up’ the cells, makes them stronger and better able to resist the destructive effects of the damaged gene that causes the disease.

“At the moment, we still don’t know if the drug will also work in humans.”