Nearly two thirds of primary care trusts (PCTs) in England say they offer screening for diabetic retinopathy to all those diagnosed with the condition in line with a target which should have been achieved by December 2007.
But in Yorkshire nine out of 14 PCTs are failing to offer the tests to all their patients. Seven are among the 20 worst PCTs for screening out of 150 across England.
Several screening programmes were last year temporarily suspended in the region after problems with their quality were uncovered. Latest figures covering 2009-10 show only 55 per cent of 24,000 patients were invited for screening in Bradford.
In Rotherham, only 68 per cent of 11,000 patients were offered tests, rising to 74 per cent in Calderdale of about 9,000 patients and 75 per cent in Barnsley of 11,000 patients.
Overall 90 per cent of Yorkshire's 237,000 diabetics were offered screening.
In contrast health chiefs in Doncaster, Leeds, North Yorkshire, Sheffield and Wakefield claim all their patients were offered screening using a digital camera to detect problems with the eye's retina which occur when blood vessels become blocked or leaky.
It is the leading cause of blindness among working adults in Britain but can be prevented in 90 per cent of cases if it is detected early enough.
Diabetes UK yesterday criticised failings which it warned were putting the sight of diabetics at risk and also raised concerns about the numbers of people coming forward for tests.
Gavin Terry, of the charity, said: "It is vital that everyone with diabetes receives free annual retinal screening with a digital camera. All 14 PCTs across Yorkshire were required to offer this service to 100 per cent of people with diabetes by the end of 2007 so it's totally unacceptable that, three years on, only five have met the Government targets.
"PCTs need to ensure they are promoting the importance of retinopathy screening and ensure local people with diabetes understand the seriousness of retinopathy and the impact that screening can have in preventing future eye damage. In turn, we would urge people with diabetes to make every effort to attend their appointment when invited."
Services for people in Barnsley, Rotherham and Bradford were among those hit following external reviews last year.
Nagpal Hoysal, consultant in public health at NHS Rotherham, said: "At the end of last year the service was halted for nearly four months due to issues with the diagnosis of the images.
"We have made considerable progress in screening all those patients who were due during the four-month period and have also offered further screening to those who attended in the previous six to 12 months.
"We are confident that the number of people with diabetes in Rotherham who are being screened for retinopathy will quickly come back into line with other areas across the country."
A NHS Bradford and Airedale said its service was also suspended following an external review last year.
"A thorough review was undertaken and as a result we have put in place a range of additional measures to ensure our programme reaches the required high quality standards," said a spokeswoman.
"The programme restarted from October 2009 and we plan to reach 100 per cent invitations to all patients in the near future."
Diabetes affects 2.3 million people in England but numbers are likely to increase significantly as more develop the condition due to the obesity epidemic. Already nearly 200,000 new cases are diagnosed in Britain each year.