There are esveral reasons why Daffs come up 'Blind'
If they have been planted to deep.
The foliage was cut back to soon, therefore not allowing the bulb to absorb the nutrients in the leaves
Daffs have their own food storage in the form of the bulb, but it is a good idea to give them a feed aswell, especially a high phosphorus application.
Narcissus Flies can be a problem too if you are unlucky enough to get those. They eat the flower buds, so cultivating around the area will help kill the larvae that are in the soil by exposing them to birds.