Use masking tape to cover all but a narrow strip on the front site, in any shape you want. Use Wite-Out or florescent paint to paint the exposed area, then remove the tape. Yes, I've done it and it's more accurate as you expected. It's also reverse-able if you go the paint route.
I'm outta here---Happy Shooting!
Ed
The Airgun Tune-Meister
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"We can rebuild the squirrel. Make him stronger, faster...We have the technology"---Skyler M.