I am in a similar boat to you vision wise OP, left eye is good, short sighted but good. Right eye is just there to look pretty, it doesn't do much if anything.
With both eyes open and my glasses on I can see well enough to drive and to not be registered as partially sighted. My VA in my bad eye with glasses on is 6/42, but my good eye makes up for it.
To be registered as partially sighted you need to meet a specific set of criteria: www.rnib.org.uk/your-eyes/navigating-sight-loss/registering-as-sight-impaired/the-criteria-for-certification/
To be certified as sight impaired (partially sighted) your sight must fall into one of the following categories, while wearing any glasses or contact lenses that you may need:
• Visual acuity of 3 / 60 to 6 / 60 with a full field of vision.
• Visual acuity of between 6 / 60 and 6 / 24 with a moderate reduction of field of vision, cloudiness in parts of your eye, or your lens has been removed and not replaced with a lens implant
• Visual acuity of 6 / 18 or even better if a large part of your field of vision, for example a whole half of your vision, is missing or a lot of your peripheral vision is missing.
Based on the definition given of police requirements provided by PP above it looks like you will not meet them.