-5.00 SPHERE and -0.25 CYL (Astigmatism) does not make you -5.25!
If anything it would make your Spherical Equivalent -5.12 which is such a small number would not change your correction in your glasses.
Sphere is the Near/Far correction and Cylinder is the astigmatism or angle of the refraction / shape of the surface of the cornea....
A -0.25 astigmatism is NOTHING to worry about and the limits are -6.00 as far as i know with regards to correction. Astigmatism measurement limits on class 1 is 2.00 and you are well within this limit. Meaning you could be up to -6.00 AND have an astigmatism of up to -2.00 as well and possibly STILL get through.
Obviously there are factors other than JUST the prescription that they test for but im almost certain you could get through on this prescription as long as with correction you can achieve 6/6 (20/20) on the vision chart.
Hope this helps
JONATHAN