Most of the time, when you buy an eyepiece, the dealer will include the eye guard for no additional cost. If he doesn t, it won't hurt to ask. Tele Vue eyepieces come with eye guards as standard equipment. I own several Tele View eyepieces and I have never been disappointed with their performance. They are, however, a bit expensive.
Barlow lenses are also an important accessory.
Barlow lenses, when used in conjunction with your eyepiece, can double or triple the power of that eyepiece. The newer Barlow lenses will increase the power of your eyepiece five fold. Also captive lock screws that won't fall out. It has a short chrome barrel and captive lock screws. I would stay away from adjustable power Barlows because most of them are not compatible with certain telescopes due to insufficient focus travel.