In a simple model there are two: the objective lens and the eyepiece lens
The lenses used in reflector telescope is the concave lens.
The reflecting telescope
It depends on the type of reflecting telescope.
Refracting telescope.
simplest possible telescope
2 or 3
At least two, but may have many. Depends on the design of the telescope.
The lenses used in reflector telescope is the concave lens.
On eyeglasses? Two lenses = bifocals Three lenses = Trofocals
It depends on the particular design.
Lenses had been known for some time before the telescope was invented. No one really specifically "invented" the telescope lens, they simply used existing equipment (lenses) in a new device (the telescope).
A telescope uses lenses...
It is a telescope that uses lenses and mirrors.
the reflecting telescope uses mirrors and lenses. The refracting telescope does not include the mirrors.
The reflecting telescope
It depends on the type of reflecting telescope.
the reflecting telescope uses mirrors and lenses. The refracting telescope does not include the mirrors.