Hello, Antibiotics are prescribed for treating infection. Having a small cavity would not indicate a need for an antibiotic. If you are experiencing discomfort and any signs of inflammation around the tooth, discuss with your dentist the need to take pre-operative medication. Your dentist may recommend an anti-inflammatory medication to start shortly before the planned extraction. Antibiotics are not absolutely necessary prior to an extraction. It is important not to overuse antibiotics. Resistance to antibiotics are a risk. Blindness is generally not a risk with an extraction. Complications from an extraction, infection with the spread of inflammation, and an unusual nerve anatomy may result in some possibl conditions that may involve eye function. Paresthesia is a risk associated with injections and possible with extractions. This would be numbness remaining instead of wearing off as normally expected. Often with time this will diminish unless there is a tual nerve damage. Preoperative x-rays are taken to evaluate root proximity to nerves. You should review all possible complications and your medical history impact with your dentist prior to the extraction. Thank you for your inquiry. I hope you feel better about having your extraction and that my comments have been helpful to you.