SPECTACLE maker Swank International Manufacturing has announced profits after tax of $41 million for the 13 months ended December 31 and a bonus warrant issue, saying it has recovered from the previous year's troubles in Europe and the US. The group has changed its year end, and the previous figures cover the 12 month period to November 1991. No annualised figures were given. Profits for the previous period were $22 million. The company reported a turnover rise to $734 million from $465 million. Describing the results as ''favourable'', the company announced a final dividend of five cents, taking total dividend to 7.5 cents, against a total dividend of seven cents for the previous period. The bonus warrants are one-for-five and expire in June 1995. Chairman Lam Yin-sang said demand for the company's products in Europe and the US had risen rapidly in the second half of last year. He also gave details of expansion plans in China based on opening retail counters. The group wanted to have its own retail counter in every big city in China this year, Mr Lam said.