The Swedish 1-m Solar Telescope is a refracting solar telescope at Roque de los Muchachos Observatory, La Palma in the Canary Islands. It is run by the Institute for Solar Physics of Stockholm University. The primary element is a single fused silica lens, making it the largest optical refracting telescope in use in the world. The Swedish 1-m Solar Telescope, with a lens diameter of 43 inches, is technically larger than Yerkes Observatory, only 39 inches are clear for the aperture. The SST is most often used as a Schupmann telescope, thereby correcting the chromatic aberrations of the singlet primary.

Adaptive optics (AO) is a technique of precisely deforming a mirror in order to compensate for light distortion. It is used in astronomical telescopes and laser communication systems to remove the effects of atmospheric distortion, in microscopy, optical fabrication and in retinal imaging systems to reduce optical aberrations. Adaptive optics works by measuring the distortions in a wavefront and compensating for them with a device that corrects those errors such as a deformable mirror or a liquid crystal array.