Some eyepieces can really stymie those who need to use prescription glasses for optimum viewing. In fact, the miniscule eye relief offered by most eyepieces at higher powers can be uncomfortable for anyone. Lanthanum eyepieces cure that problem and offer superior performance as well. Each is endowed with generous 20mm eye relief. That means no more scrunching your eye right up to the glass, even with high power (short focal length) eyepieces. Best of all, if you wear eyeglasses, you can keep them on and still take in the entire field of view!
One of the six to eight lens elements is made from Lanthanum, a “rare earth” element that provides virtually total freedom from visual aberrations. Multilayer coatings on every air-to-glass lens surface yield the very sharp, bright, high-contrast images needed for serious planetary and deep-sky observing. Most eyepiece designs sacrifice eye relief (i.e., comfort) as power increases. This one has a full 20mm of eye releif. Threaded for filters. Soft pop down rubber eyecups. Apparent field 45° 1.25" barrels. 6MM $75 shipped