The health professional will continue to test your eyes with different lenses until it is determined which lenses correct your vision the best.
Spectacles or eyeglasses also use lenses to correct a person's vision.
Once in place, the artificial lens unfolded and now corrects the lifelong poor vision in that eye.
A cylindrical lens of the right power can correct this kind of blur.
However, Eck is unable to see properly in three-dimensional space, and requires lenses to correct his two-dimensional vision so that he can find the rift.
Another anamorphic lens on the movie theatre projector ultimately corrects (optically decompresses) the picture.
"The painter has rendered distortion so exactly," Doty remarks, "that the lens corrects it perfectly."
Some spherical rigid lenses can also correct for astigmatism.
These lenses may also correct refractive error.
Rigid lenses can also correct for corneal irregularities, such as keratoconus.