A software designed for ophthalmic functions converts a unfavourable cylindrical lens prescription to its optimistic counterpart. For instance, a prescription of -2.00 sphere, -1.00 cylinder, and 90 axis could be transposed to -1.00 sphere, +1.00 cylinder, and 180 axis. This transposition represents the identical corrective energy however expressed in another way.
This conversion provides a number of sensible benefits in optometry and ophthalmology. Transposing to plus cylinder permits for simpler lens fabrication in some cases and might simplify particular calculations associated to lens mixtures and prescriptions. Traditionally, totally different regional preferences and manufacturing methods contributed to using both plus or minus cylinder notation, necessitating a technique for readily changing between the 2 varieties. This stays related at this time for worldwide communication and consistency in lens prescriptions.