The CBD cannabis oil, has many therapeutic properties, while lacking the narcotic effects, present in the THC cannabis oil.
The anti-inflammatory properties of CBD-for your purposes-would be substantial, however, regarding the vision improvement and CBD, there's no research data to go by.
I would suggest you ask your Ophthalmologist, if cholinergic eye drops would be safe as a pupil constrictor
Hope this helps,
Niko
Generally, drugs classified as opioids will constrict pupils when the drug is ingested. During use, opioids tend to stimulate the parasympathetic nerve and cause constricted pupils.
The resulting visual phenomenon is known as the "pinhole" effect.
Hope this helps,
Niko