If i've been leaving early quite a bit the past two weeks, do i need to tell my employer why?

If you're a salaried employee, you likely have some flexibility with your hours. However, if you're an hourly employee, you should be getting permission from your supervisor well in advance prior to leaving early. If you are an hourly employee, you need to get approval from your supervisor -- otherwise, you might find yourself written up or fired (depending on company policy). You don't have to give too much information, you could simply tell them that you had a few appointments scheduled over these two weeks, but that you tried to make them as late in the day as possible. If your current employer doesn't offer health insurance, look into purchasing private insurance (even if it's just to cover emergencies) or look into your state insurance programs. Otherwise, a car accident, fall, or emergency surgery can easily cost you tens of thousands... which could financially devastate you for awhile. Don't send an email if they can be reached by phone. Ideally, you should have contacted them at least 2 weeks in advance if you're hourly. If you're salaried, just send them an email to let them know that you'll be leaving 30 minutes early due to an eye appointment.