Seiko has reported a downturn in its optical products business for the first half ended Sept. 30, with net sales down by 10 percent to ¥12.6 billion (€97.0m-$145.8m). The operating loss for the segment was ¥0.3 billion (€2.3m-$3.5m), a worsening from the zero operating income reported for the same period in 2008. The company overall had a 21.6 percent decrease in sales to ¥71.1 billion (€547.3m-$822.5m), and the group's operating loss was ¥3.5 billion (€26.9m-$40.5m), against income of ¥1.0 billion last year.