While PPG Industries had a 30 percent drop in sales to $2.8 billion for the first quarter, its optical and specialty materials segment, which includes Transitions Optical and PPG's optical materials business, fell by 17 percent to $245 million. The company attributed the drop to lower sales volumes and foreign currency conversions. Earnings for the segment fell by 18.9 percent to $60 million on the lower volumes. PPG overall had a loss of $111 million compares with income of $100 million in the same period of 2008.