To confuse prescription writing, the same cylindrical error may be expressed in positive or negative numbers depending on the degrees of axis measured. The final component of a corrective lens prescription is the accommodation or correction for presbyopia. This denotes the curve of the lens to be used in the bifocal portion of the lenses. The Add is always listed last in the prescription. When discussing the vision using both eyes, the term O.U. is used.
Corrective lenses can be either glasses or contact lenses.
In other words, the lenses must be available in the aircraft for reading but do not need to be worn continuously. Both bifocals or contact lenses for distant used with reading glasses for near meet this requirement. Again, use of monovision and multifocal contact lenses is prohibited. For a more specific personal explanation to your questions or those concerning aeromedical certification, contact VFS for a private consultation . For help in reporting treatment for and obtaining clearance from the FAA to fly with these conditions, refer to the VFS FAA Liaison Center .