How many lenses do oculars have?

Ocular lenses, commonly referred to as eyepieces in optical instruments like microscopes and telescopes, typically contain one or two lenses. A single-lens ocular is simpler but less common, while most modern eyepieces use a compound design with two or more lenses to improve image quality and reduce optical aberrations. Therefore, the number of lenses in oculars can vary, but they generally feature multiple lenses for optimal performance.