inappropriate to a UK based health technology assessment more than 10 years later. Another approach taken when conducting cost utility analyses is to only include the cost of treatment and ignore the costs averted. This can be done if a "for profit" third party insurer perspective is taken, but again not if a publicly funded health service or societal perspective is taken. 6 The support that different countries' public health, social provision, or health insurers give to people who become blind is also important. In general, the more support that is given the higher the cost. Since provision is different, the cost of blindness calculated in one country may not be applicable to another. Also, the low vision threshold at which benefits accrue may vary. Legal blindness is defined differently by different countries or organisations but a fairly standard definition is visual acuity of 6/60 (or 20/200) or worse in the better eye or a visual field less than or equal to 20 degrees in the better eye. In England and Wales a certificate is issued called a BD8. On this, the legal definition of blindness is "so blind as to be unable to perform any work for which eyesight is essential." The visual acuity recommendations are 3/60 or worse in the better eye (corrected visual acuity) or 6/60 or worse in the better eye with markedly restricted fields. The issuing of a BD8 certificate starts a process of assessing needs and providing appropriate services. Obviously, the BD8 definition was