Mir has it right. Most airlines will write the "runway in sight" into the ops manuals. But this is not an EU Ops requirement.
For smaller aircraft, like SEP, there would be no problem to request a visual in 800 meter RVR and flight visibility, when you see "the factory with the chimney and the highway besides that leads to the airport".
Also, EU-Ops doesn't specify which part of the approach you conduct visually. That means, you can request a visual to shorten your initial approach (avoid flying a full procedure in mountainous terrain), and complete the approach using the e.g. the ILS - that is if your airline allows you to request visual without the runway in sight.
Last edited by cosmo kramer; 14th February 2013 at 12:59.