1. From the The Smith-Kettlewell Eye Research Institute, San Francisco, California;
2. From the The Smith-Kettlewell Eye Research Institute, San Francisco, California; the 2Department of Psychology,
3. the Department of Pediatrics, School of Medicine and 4Healthy Start Pediatrics, Mountain View, California.
4. the Department of Biological Sciences, Stanford University, Stanford, California; and
5. the Department of Pediatrics, School of Medicine and