Go to a different optician and get their opinion. If they say it needs doing have it done. If the other eye is OK leave it alone.
My eye consultant, after rebuilding my eye damaged by a nasty internal infection, said that he had to replace the lens. I can now see perfectly though that eye. The other eye was still bad (I had measles as a 2 year old which damaged my eyes and specs have been essential for all my waking hours ever since, 67 years worth of specs!) He said it would need doing as my eyes were so mis-matched, but he would like to wait, as he didn’t like to do both at the same time. This was NHS and the treatment was amazing!