The higher the index, the more reflections off the surface and the thinner the lens can be made. That is why anti-reflective coating is a good idea for high index lenses. Aspheric lenses are also a good choice with your prescription.
Generally, each lens materials can block some light from passing through the lens. This light reflects back from the lens surface, causing distractions and reducing the clarity of night vision.Conventional glass or plastic lenses or polycarbonate lens can reflect about 8 percent of light that otherwise would reach the eye. High-index lenses reflect up to 50 percent more light than conventional glass or plastic lenses/polycarbonate lens.
Polycarbonate and Hi-index lenses are both excellent products. As long as you have a good quality anti-reflective treatment applied to the lenses. you shouldn't be bothered by reflections in either product. There are differences in anti-reflective treatments, be sure you understand what you are getting. Some are very scratch resistant, they don't peal or craze easily, and they clean very easily. Others damage easier and don't last as long before causing visual problems. If your optician feels polycarbonate is a good lens for you, he/she is probably acting in your best interests in giving advice, since hi-index costs more than polycarbonate. Listen to the Optician's advice about the proper anti-reflective treatment.