The Telescope Eye, the Goldfish with poor eyesight.
wikipedia
The Telescope Eye Goldfish 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 that possess a double-tail
and dorsal fin. Telescopes occur in all of the typical colorations of
goldfish, but are most frequently seen in black.
Black telescopes are called moors.
Because their protruding eyes cause poor vision, telescopes
should ideally be kept with other fancy goldfish with impaired
vision: bubble-eyes,
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 cornia.
Like all fancy varieties of goldfish, telescopes require a
minimum of 10 gallons of water per fish, 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 40ppm.
A well kept telescope will grow to 8 inches or more in body
length.
