Distant visual acuity, with or without correction, shall be 6/9 or better monocularly, and 6/6 or better binocularly. If the visual requirement is met only with the use of correction, the spectacles or contact lenses must provide optimal visual function and should be suitable for aviation purposes. At initial examination the refractive error shall not exceed +/-3.00 dioptres along the most ametropic meridian with no more than +/-2.00 dioptres astigmatic component and no more than 2.00 Dioptres of anisometropia. If the refractive error is within the range -3/-5 dioptres, the Aeromedical Section may consider Class I certification if:
Found
here
Astigmatism is the term used.