Day, director of Pediatric Ophthalmology Units, Pacific Presbyterian Medical Center and Smith-Kettlewell Engineering Center For Low Vision and Blindness, San Francisco, is purposely having infants look directly at a camera and taking a flash photograph. When the pictures are processed, the pupils have that eerie red glow that often ruins home photos.Because that red reflex is caused by light passing through the cornea and lens, reflecting off the retina, and bouncing back the same way, Day says it can tell physicians a lot about how well, or poorly, the eye is refracting light onto the retina. Therefore it can be used to help detect conditions like unequal refractive errors in the two eyes, high refractive errors, strabismus, and media opacities; conditions, which if not diagnosed early, can hinder normal development of the visual system, leading to amblyopia.
Currently, Day says, most children do not have their eyes checked until they are at least 3 years old, when they are old enough to speak and tell the doctor how well they see the chart. But, she explains, the visual system is well on its way to full development by that time, and therefore, diagnosis of any problems often comes too late to prevent amblyopia.
Day uses a conventional 35 mm camera with a commercially available mirror telephoto lens mounted on a tripod. The camera flash is fixed directly below the lens, to position the lens closer to the flash than it would be in the conventional position. The infant or young child is held in the mother’s lap, about 4.5 m in front of the camera. You can shop with a reliable pharmacy – buy antibiotics online here to pay less for high quality.