There could be few finer ways to pass a dreary afternoon than exploring the radiant survey of light-based artworks on show at London's Hayward Gallery, an illuminated journey so warming - at times literally - that it becomes a foil for our mid-winter reality.

'Light Show' spans generations of light-obsessed artists, from Dan Flavin's early investigative neon works through to Leo Villareal's sparkling new shower of LEDs 'Cylinder II', the dazzling face of the exhibition. With the exception, perhaps, of Iván Navarro's claustrophobic one-way mirrors, it is a tremendously welcoming show. Some of the works require you to watch and ponder for 10 minutes or more before you can appreciate them fully. Sit down, they implore. Bask in the light.

Dr Cliff Lauson, Hayward's curator, has created 'experiential, sensual' environments that 'hit a spectrum of emotive tones. It can be subtle,' he says, referencing Cerith Wyn Evan's light pillars, which from a distance appear beautifully birch-like but up close heat up ominously like mosquito zappers. It can also unsettle you, like Conrad Shawcross' 'Slow Arc inside a Cube IV', in which a moving light splashed on a steel cage creates vertigo-inducing shadows.

Olafur Eliasson's 'Model for a timeless garden' uses strobelights to freeze the fluid movements of a dozen fanciful water fountains, a contrast that's at once captivating and off-putting. 'Light can be calming, but it can also be aggressive,' says Lauson, fairly.

The majority of works, though, are uplifting in the extreme. Venezuelan op artist Carlos Cruz-Diez challenges not only our perceptions but our eyes themselves in 'Chromosaturation', where niches of red, blue and green neon meld to form brilliant pools of tertiary colour like atmospheric Prozac.

It's quite a buzz, and not just in your ears. In the curtained-off 'You and I, Horizontal', Anthony McCall has used projections and haze to build a field of light so seemingly solid, you'll want to climb aboard. The projections vary over 50 minutes, so McCall is all for you staying for the extended release. And besides, he says, 'After you've been in there five minutes, it doesn't feel dark any more.'