A pre-health journal is a useful tool for reflecting on your interests and preparing for the admissions process. You can begin a file on your computer or start keeping a notebook as a journal. Use it to record any thoughts about your interest in healthcare, and optometry in particular. You could write about the experiences that initially sparked your interest in healthcare, or more recent experiences that confirmed a career in optometry is the right fit for you.
You may find that when you sit down to write, you start out with one thought, which leads to another thought and then another, and you find that you have thought about something that you never thought about before. Often you will get more out of activities if you spend some time writing about them and reflecting upon what you have experienced.
Keeping a pre-health journal of reflections throughout your clinical and volunteering experiences can help you later when it comes time to write essays for your optometry school application and prepare for admissions interviews.