LED光源目前广泛应用于照明工程和信息技术，有望成为未来生活中的主要光源之一。尽管LED得到了广泛且迅速的应用，但物理光测量、视觉和光生物学评估的可靠方法仍存在疑问。CIE在1997年和2001年成功组织了两次LED研讨会。然而，仍然有许多问题没有解决，例如部分通量和辐射度的测量、视觉评估（如显色）或光生物安全要求。为了讨论这些问题，CIE第1、2和6分部在CIE日本全国委员会和AIST日本分会的支持下，于2004年6月7日至8日在日本东京滨水区的AIST（国家先进工业科学技术研究所）举办了LED光源专家研讨会。 会议分为四个主要环节:•色彩渲染•视觉•光生物安全•测量。阅读了关于“用于未来照明系统的LED的物理和视觉要求”和“发光二极管发出的白光”的主题论文。研讨会还包括一个海报会议。会议记录包含所提交的30篇论文的同行评审版本，以及讨论会的摘要。CIE x026:2005是会议记录的第二版，包括所有提交的完整论文。该出版物共有155页，其中138幅主要是彩色数字。

LED light sources are now widely used in illuminating engineering as well as in information technology and are expected to be one of the major light sources in our future life. Despite the wide and rapidly growing use of LEDs, reliable methods for physical light measurement and visual and photobiological evaluation are still in question. The CIE had organized two successful symposia on LEDs in 1997 and 2001. However, there are still many questions left unsolved such as measurement of partial flux and radiance, visual evaluation such as colour rendering, or requirements for photobiological safety.To discuss these issues, CIE Divisions 1, 2 and 6 organized this expert symposium on LED light sources, held from 7 to 8 June 2004 at AIST (National Institute of Advanced Industrial Science and Technology) Tokyo Waterfront/Japan, with support from the Japanese National Committee of the CIE and AIST Japan.The meeting was divided into four main sessions:• Colour Rendering• Vision• Photobiological Safety• Measurement.Keynote papers were read on "Physical and visual requirements for LEDs to be used for future lighting systems" and "White light from light emitting diodes". The symposium included also a poster session. The Proceedings contains the peer-reviewed versions of the 30 papers presented, as well as a summary of the discussion sessions. CIE x026:2005 is the 2nd edition of the proceedings and includes all full papers that were submitted.The publication contains 155 pages with 138, mostly coloured, figures.