The Telescope eye is a type of goldfish characterized by its protruding eyes. The eyes are situated at the end of what is called the eye-stalk. Telescopes are a variety of fancy goldfish and possess a double tail and dorsal fin. Telescopes occur in all of the typical colorations of goldfish, but are most frequently seen in orange, calico, panda (black and white), and black, which is often referred to as a black moor.
Because their protruding eyes cause poor vision, telescopes should ideally be kept with other fancy goldfish with impaired vision: bubble eye, celestial eye, or other telescopes. Sharp gravel and ornaments can damage their eyes, and should not be used. Telescopes are also more susceptible to a condition called “cloudy eye”, a bacterial infection resulting from damage or scratching of the cornea.
Like all fancy varieties of goldfish, telescopes require a minimum of 10 gallons of water per fish, with a minimum ideal tank size of at least 55 gallons, and a lot of filtration. As a fish grows, it is sometimes necessary to expand this rule to 3 gallons per inch of fish-body. Tank water must be changed weekly in sufficient amounts to keep nitrate levels below 4ppm. A well kept Telescope will grow to 8 – 10 inches in body length.
Because of the more sensitive nature of the Telescope eye, they are not suitable for beginners.
It is sometimes referred to as Globe eye goldfish in the United Kingdom, or as the Dragon eyed goldfish.