TC 5-6----what is FC? If it's less than 5-6 you have CC and need to "shock" your pool to get rid of it. CC irritates eyes.

pH 7.4--try raising pH to 7.6-7.8--higher levels are easier on your eyes.

You can also try adding salt (sea salt) to your water. Many people find mild levels of salinity to be more comfortable--eye drops and tears are salty.

I'm not sure (again, Chem_Geek and Waterbear!) but higher borate levels may also be more comfortable (You get that by adding Borax).

Finally, if nothing works, you can find a comfortable pair of swim goggles. Ultimately, they are better for your eyes than exposure from swim water. I ALWAYS use them when I swim laps, along with earplugs.