My cat needs help...

Hey reddit, my cat (and I) need help. He's an old one and has been with me for many years. However, I learned recently he's developing cataracts and is slowly going blind.

For the past year or so he's been having odd tantrums, though recently they're growing to be more numerous as well as intense. At first I suspected this was all merely psychological, although I'm beginning to suspect they're being caused by the gradual darkness enveloping his field of view. He's losing his ability to see, and I think he's scared.

What can I do to help him? I can only hold him so long during the day, and when he's not in my arms his terrors are growing worse. Thanks for any help or experience.