Hong Kong is as famous for its night lights as its tall buildings. One without the other is inconceivable, especially for the tourists who line the Tsim Sha Tsui waterfront nightly to watch the Symphony of Lights show. But there are those who think it's too much - that the dazzle isn't worth the energy wasted, air pollution created and annoyance to people living in the beams of lasers and spotlights. Light pollution is without doubt a problem in some areas, but with so many interests at stake, changing our ways has to be less a matter of using the off switch and more a question of getting the balance right. There's no doubt that lighting is sometimes used to excess. Shops that burn lights overnight have long been a problem. Streets can at times be as bright as day; Nathan Road in Mong Kok on any evening ably proves the point. We need to tone down our usage. Environmental groups like Friends of the Earth have long been campaigning for lights to be dimmed and, where wasteful, extinguished. The economic downturn helped out, making shop owners turn to more economic use of lighting to cut costs. But the environmentalists say that's not good enough: a draft law sent last week to the Environmental Protection Department for consideration sets out strict rules that they say should be mandatory, not voluntary. Among the measures are a curfew on outdoor advertising, ornamental and non-functional lighting between 11pm and 7am, limits on outdoor light intensity, a mechanism to report complaints and an end to the Symphony of Lights. Increasing numbers complain about light disturbance - there was an almost 60 per cent rise last year over 2008. We have environmental obligations to use energy-efficient lighting. Turning off lights when they are not needed uses less electricity, which means less pollution from power stations. Education is a valuable tool in such circumstances to teach common sense and courtesy. Hong Kong is known to many as a city of lights. Millions come here each year with that expectation; there is no reason to disappoint them. Lights have to be used responsibly. Sympathetic management by authorities, not heavy-handed regulation, is what is required.