Pretty sure there is no uncorrected standard any more as the Euro license only specifies criteria that you can see not whether that's aided or not.
"(2) The following requirements as regards vision must be complied with
(a)aided or unaided distance visual acuity: 1,0; minimum of 0,5 for the worse eye,
(b)maximum corrective lenses: hypermetropia + 5/myopia -8, (derogations may be authorised in exceptional cases and after having obtained the opinion of an eye specialist, the recognised doctor then takes the decision),
(c)near and intermediate vision: sufficient, whether aided or unaided,
(d)contact lenses and glasses are authorised when periodically checked by a specialist,
(e)normal colour vision: use of a recognised test, such as Ishihara, as well as another recognised test if required,
(f)field of vision: full,
(g)vision for both eyes: effective; not required in a case where a person loses binocular vision after starting job as train driver when that person has adequate adaptation and sufficient compensation experience,
(h)binocular vision: effective,
(i)recognition of colour signals: the test must be based on recognition of single colours and not on relative differences,
(j)sensitivity to contrasts: good,
(k)no progressive eye disease,
(l)lens implants, keratotomies and keratectomies are allowed only on condition that they are checked on a yearly basis or at intervals set by a recognised doctor,
(m)ability to withstand dazzle,
(n)coloured contact lenses and photochromatic lenses are not allowed, but UV filter lenses are allowed."
From
http://www.legislation.gov.uk/uksi/2010/724/schedule/1/made