Phalaenopsis dark withered leaves

[cra323]

I’ve had this orchid for 10 years now. A couple years ago, I noticed it’s leaves would get dark, splotchy, and withered almost as soon as they grew in. It continues to bloom, grow roots, and put out new leaves, and I thought it would eventually grow out of whatever problem it was having, but alas. Does anyone have any idea what this could be, and how I can fix it?