Just make sure your planning is spot on, and always be prepared for low viz. Always plan to avoid gliding sites, impossible to see gliders even on good viz days.
If you have to make diversions, make sure you are up-to-scratch with a technique, before you set off on an unplanned course. If not, you could end up with more problems.
Always try to be on frequency with a radar service, preferably RIS, nice to have someone looking out for you.
There's nothing you can buy that lets you see through haze or cloud.