Researchers sometimes place images in Web surveys to motivate participation or to illustrate the meaning of a question, but studies indicate that presenting an image affects responses (e.g., Couper et al. 2007; Couper et al. 2004). To date, this research has investigated changes in responses based on the type of image presented; for example, how presenting an image of grocery shopping versus clothing shopping changes reports of shopping frequency (Couper et al. 2004). Our study extends this research by examining how quantity depicted in images affects respondent reports. Respondents will be randomly assigned to receive one of two Web surveys. One version will present pictures of one cigarette and one alcoholic beverage as illustrations for smoking and drinking behavior questions. The other version will present images with multiple cigarettes and glasses of alcoholic beverages for the same questions. We hypothesize that the respondents in the single cigarette and alcoholic beverage image condition will report consuming fewer cigarettes and alcoholic beverages compared to respondents in the condition in which many cigarettes and alcoholic beverages are depicted. Moreover, we hypothesize that the quantity depicted in the images will affect how respondents consider themselves as heavy versus light smokers and drinkers. Respondents may compare themselves to the quantity presented in the image to judge whether they smoke and drink heavily. In addition to analyzing differences in respondent reports, we will use eye-tracking data to analyze the time respondents spend looking at the image and the frequency with which they look between the images and the questions and response options to try to further understand how images and their content affect survey responses. We will conclude with implications for the use of images in Web surveys and Web survey design in general.