Recent studies have found that electroretinogram (ERG) can be used for diagnosis of neurodevelopmental and neurodegenerative disorders. An inexpensive ERG system that sends data to a smartphone for further processing could help the widespread use of ERG and its application for early detection of neurodevelopmental and neurodegenerative disorders like autism spectrum disorder and attention deficit/hyperactivity disorder on critical patients such as kids. The ERG response is a mass electrical response from the retina, evoked by a brief flash of light. The ERG is composed of electrical potentials contributed by different cell types within the retina, and the stimulus conditions can elicit stronger response from certain components. This light stimulus can be created using a smartphone flashlight , however, the resulting ERG signals are very small and typically are measured in microvolts or nanovolts. This is the reason why the response to a flashlight is needed to be amplified , filtered and processed on a designed PCB circuit board with data storage and communication capabilities.Finally , the data is transmitted to a smartphone for its visualization and enabling real-time smartphone analysis for faster diagnosis and research.