Illumination optics is a multidisciplinary effort: a good optical engineer should understand the language of physics, mathematics, computer science, materials science, process engineering, cost engineering, psychology, visual perception, marketing, design, lighting standards and regulations. The transition to LED lighting changed the rules of optical design in most of these aspects. The absence of IR and UV light enabled the use of plastic optical components, which allows for a huge variation in optical solutions. This in turn completely changed the appearance of the luminaires and allowed for more precisely trimmed intensity distributions. When these new luminaire types entered the market, people started to question whether the lighting standards, which were defined in the days of fluorescent tubes and incandescent lamps, were still valid for LED-based luminaires. These changes will be illustrated with optical designs of office lighting luminaires. The impact of LED-based luminaire designs on discomfort glare perception and glare standards will be addressed.