The species is so called due to the black eye patch, surrounded by a white ring. The Spectacled porpoise is a rarely seen and little-known animal, which have been observed only a few times. This animal is distinguished from other porpoises by its small head as well as unusual facial features and coloration. The upper-parts are black, while the under-parts are white. Small flippers of the animal are located far forward on the body. The dorsal fin is considerably large and rounded in males, being smaller and more triangular in females. The back of young porpoises is dark grey, whereas the under-parts are light grey.
The Spectacled porpoises are distributed across the southern Atlantic, Indian and Pacific Oceans. The Antarctic range of these animals stretches from the eastern coast of South America in the south to southern Brazil in the north. In the Pacific Ocean, the area of their distribution stretches northwards, reaching Tasmania and New Zealand. The usual habitat of the spectacled porpoise is cold ocean waters of the southern hemisphere. The animal typically occurs around offshore islands, less frequently - in the open ocean. This porpoise favors cold currents on the sub-Antarctic area such as the Falkland Current.
Because of being quite a rare and insufficiently explored species, little is known about the biology and habits of the Spectacled porpoise. The animal is thought to be solitary, since it is generally seen alone, though small groups, consisting of three individuals (evidently, a female, a calf and an additional adult), have also been recorded. When coming to the surface, the animal is usually hard to notice, as it raises only a small part of its body in order to breathe. When noticing an approaching boat, the porpoise immediately swims away. Presently, there is no information on the migratory behavior of this porpoise; moreover, it's unknown if the animal is migratory at all.
There is very scarce information on the diet of the Spectacles porpoise, though the animal is thought to be piscivorous and share similar diet with other porpoises, consuming fish, squid, and crustaceans.
Nothing is presently known about the mating system of this animal. Meanwhile, there is very little information on the mating behavior of the Spectacled porpoise. Thus, females are believed to give birth in early spring or summer, but there is no evidence to support this assumption. Gestation period lasts for 8 - 11 months, yielding a single baby. Females of this species are sexually mature at 2 - 3 years old, whereas males reach maturity within 4 years.
The Spectacled porpoise suffers from human activity along with many other cetacean species: gill nets as well as trawling and stranding pose a serious threat to the population of this animal. On the other hand, the animal is threatened by human disturbance in a form of oil and mineral exploration, while offshore pollution causes the accumulation of toxins within the animal's body.
According to the IUCN Red List, the total population size of the Spectacled porpoise is unknown for today and the species is currently classified as Data Deficient (DD) on the IUCN Red List.