As online fashion retailing has grown immensely over the last fifteen years, retailers' website designs have had to evolve to meet customers' increasing demands, needs and expectations in order to attract and retain them. The purpose of this thesis is to provide a greater understanding of how different ages of consumers respond to retailers' holistic website designs through the use of eye tracking technology. Insights gained from this research will enable retailers to enhance their website design in accordance with their target market's behaviour, habits and expectations. Eye tracking is a key tool for analysing and understanding human-computer interaction and can be used alongside qualitative in-depth interviews to provide a detailed understanding of users' responses to the website design. This study uses the Stimulus-Organism-Response (S-O-R) paradigm to investigate how the fashion retailer's holistic website design influences users' visual, cognitive and behavioural responses, which leads to their approach or avoidance behaviour. The study also examines whether the shopper's motivation or age will have an influence on their responses to the website design. It is important to analyse the differences in behaviour between age groups because more mature consumers are now shopping online, and academic research on this topic is limited. A sample of 50 participants, spanning ages 20 to 70 and consisting of regular users of the website, participated in the study. The study was conducted on the fashion retailer's live website and results were recorded in real time, making the findings more valid. The study found that users were very focused on looking for products when shopping online and that the product listings page is arguably the most important page on the website as users visit it the most and spend the most time on it. Furthermore, the study found that navigation and customisation design stimuli were the most important to users and that they did not to pay much attention to the lower sections of the web pages. The study also found that users' responses to the website can change according to their motivation as users spent less time on the website if they were goal-directed shopping and had more focused viewing patterns than if they were browsing. Moreover, the study also found that different age groups had different responses to the website design, as older users took longer to navigate the website and had slower viewing times than younger users, and also looked at the thumbnail images that were further down the page a lot less. This research has filled a gap in the academic literature and provided a detailed understanding of eye fixations, and how they can be interpreted in website design studies. Future academic studies on retailers' website design can assume that long fixation durations indicate positive attention. Also, the findings enable retailers to understand how the design stimuli affect different ages of users' shopping experiences and, as a result, can design their website according to their target markets' behaviour. Furthermore, this study highlights the areas that are not capturing users' attention on the website, and that need to be improved by retailers. Overall, the findings suggest that retailers should focus on providing an easy, efficient and quick shopping experience for users when designing their website.