Unfortunately ............................
........................ your port lenses are succumbing to the life and death cycle that all acrylic experiences. The main cause of the deterioration is UV radiation.
As the minute cracks are internal, the only solution is to replace the lenses.
If you do decide to go this route, you'll find a large amount of material which has been written on the subject which can be found under the search menu.
But on the positive side of things .................... welcome to the site.