Smart glasses are increasingly being used in professional contexts. Having key applications such as short messaging and newsreader, they enable continuous access to textual information. In particular, smart glasses allow reading while performing other activities as they do not occlude the user's world view. For efficient reading, it is necessary to understand how a text should be presented on them. We, therefore, conducted a study with 24 participants using a Microsoft HoloLens to investigate how to display text on smart glasses while walking and sitting. We compared text presentation in the top-right, center, and bottom-center positions with Rapid Serial Visual Presentation (RSVP) and line-by-line scrolling. We found that text displayed in the top-right of smart glasses increases subjective workload and reduces comprehension. RSVP yields higher comprehension while sitting. Conversely, reading with scrolling yields higher comprehension while walking. Insights from our study inform the design of reading interfaces for smart glasses.