A research team, based at the School of Optometry, University of Alabama, USA, have published data showing that nicotine by itself dramatically reduced the dark-adapted b wave amplitude response in human volunteers. Under light adapted conditions the peak b-wave amplitude was also significantly decreased. The study, conducted by Dr. Stefanie Varghese and Dr. Kent Keyser, examined the effect of nicotine (2mg and 4mg) in ten visually normal non-smoking adults. The administration of nicotine in the form of a gum 30 minutes prior to testing ERG responses were analysed using a full field ERG system.