List of largest optical refracting telescopes

The Swedish 1-m Solar Telescope, with a lens diameter of 43 inches, is technically the largest, with 39 inches clear for the aperture.The second largest refracting telescope in the world is the Yerkes Observatory 40 inch (102 cm) refractor, used for astronomical and scientific observation for over a century.

[1] Most are classical great refractors, which used achromatic doublets on an equatorial mount.

However, other large refractors include a 21st-century solar telescope which is not directly comparable because it uses a single element non-achromatic lens, and the short-lived Great Paris Exhibition Telescope of 1900.

As with reflecting telescopes, there was an ongoing struggle to balance cost with size, quality, and usefulness.

98 cm (39") clear aperture Detroit Observatory in Ann Arbor in use for the public