Although an oblique font can be generated by simply tilting the base font, some designers use optical correction to correct the distorted curves this introduces.
Their surveying skills were exceptional, enabling them to set out the incredibly exact optical corrections of buildings like the Parthenon, although the methods used remain a mystery.
Pancake lenses can be very short and flat because they do not need large amounts of optical correction, i.e. extra lens elements.
In addition, the obliques are altered from the original, where optical corrections are no longer used.
In terms of treatment, the most effective optical correction is still being researched with respect to visual field angles and direction to a target.
Contact lenses, now sometimes used with very young children as well as older pupils, provide optical correction in another form.
The italic fonts were redesigned to include optical correction.
Other optical corrections will be left to traditional glass or plastic lenses.
The exceptional detail of the goatskin cloak, the beard and the hair accompany of series of optical corrections.
The woman wore huge glasses in brown, homrim frames, but the optical correction in the glass was so large that her eyes were comically enlarged.