Be jaw dropping in this open-back long mermaid prom dress by Eureka. With beaded-lace floral embellishments from the deep neckline to the hem, this long special-occasion dress gets a sparkly look for prom, galas, and other formal events. Thin shoulder straps lead to the open back of this long formal dress, while the hip-skimming long skirt flows to the floor in a mermaid shape. Offered in misses and some plus sizes, this open-back long mermaid prom dress is surprisingly affordable at under $200.