Binocular eyecups are suffer constant wear-and-tear. After years of use it may be necessary to replace them. Some manufacturers - especially those from the high-end sector - offer a spare parts service for this.

Swarovski
Winged eyecup set
$ 45.90
ready for shipping in 3-7
days

Leica
Noctivid winged rubber eyecups
$ 59.00
ready for shipping in 3-7
days

Leica
Side light shields Geovid HD-B/HD-R
$ 47.90
ready for shipping in 3-7
days

Kowa
Special eyecup for Highlander eyepieces
$ 42.90
ready for shipping in 24
h