|Narrow-band imaging in the infrared is one of the most promising way to discover the z~7-10 lyman emitters, possibly responsible for the re-ionisation of the Universe. I will describe the ZEN (Z Equal Nine) VLT survey for lensed and non-lensed lyman alpha emitters at these redshifts. Although we do not detect any ZEN galaxy so far, we can already place a useful upper limit on the surface density and on the luminosity of such objects. Given these limites, future prospects to detect ZEN galaxies with|
large field IR imagers are very good.