The species Exacum affine is commonly known as the Persian violet or German violet. Exacum affine is a species of plant in the Gentianaceae family, which is endemic to Socotra islands of Yemen. Its natural habitat is rocky areas. Violet-blue, five-petaled flowers are studded with yellow centers, called “eyes", and rise above a mound of small glossy green leaves. The flowers are fragrant, but the pollen may cause an allergic reaction!
Pinch off the flowers after they fade - this will promote more blooms. Another idea is to move your plant to a brighter location, out of direct sun. Raise the humidity around it by placing the pot on a tray of wet pebbles. Sometimes plants are in shock when you bring them home, and this will help it adjust to its new home!
Dry soil will cause flowers to fade quickly. For this reason, keep the soil moist at all times, but don't overwater. If you're watering regularly and the plant wilts, root rot is likely. This is the most common problem with this plant.
Exacum plants are a biennial, although it is usually treated as an annual and tossed out after flowering. If you want to over-winter the plant, prune it back harshly and keep it above 60°F/16°C. You can collect its seeds the second year.