Grass seed for shady areas?

I am in the process of dealing with a ghastly jungle area which has not been touched for at least 15 years. I have cleared away a fallen down metal fence (thank god for bolt cutters!) and various climbers which were climbing up said fence (Mile a Minute, Honey Suckle, Clematis) all looking terrible due to being under an ENORMOUS Lime and no I didn't plant them!
Once I have cleared the area I intend to grass it. Obviously I am not going to get grass to grow right up to the trunk of the tree but was wondering if grass seed sold specifically for shady areas is any better than bog standard or is it a good way of increasing the price of the seed and just a load of sales spiel? Thanks.

 

I used Wilko's second cheapest general purpose/hard wearing lawn seed when I did mine 2 or 3 years ago. We have next door's massive sycamore overhanging much of it, a 6ft high fence on the east boundary, and the garden is sort of north west facing. All this adds up to mean that although the full lawn does get some direct sunshine at various points in the day, it is generally a fairly shady garden most of the time, yet the grass thrives.

 

I had a dreary patch here where the lawn was a disaster in an area dank from being heavily shaded. Re-sowed with "Shady Mix" and it is much better now (I leave the grass a bit long [my choice, don't know if that is actually necessary], but other than that I would describe it as "Normal lawn looking")

I have bought from two sources in the last few years:

www.bostonseeds.com/products/1/Grass-Seeds/1/Lawn-Seeds/
http://www.lawnsmith.co.uk/shop/grass-seed

Can't remember which one I got the shady grass seed from though! Both have provided good service etc.