The 60-year-old lives with hearing and visibility impairments in the rural township of Castlemaine, in central west Victoria.
He has received funding from the National Disability Insurance Scheme since 2021, when he was given access on the basis of those impairments.
The following year, he asked the agency behind the scheme for $7833 to buy a mobility scooter so he could travel into town independently for shopping, medical appointments, family visits and volunteer work.
Public transport options are limited in the regional town and his disabilities, including physical impairments, make his daily commute difficult.
The National Disability Insurance Agency denied the funding request, arguing Mr Eastham needed the scooter for his mobility issues, not the vision and hearing impairments that qualified him for the scheme.
He successfully challenged the decision at a tribunal and again at the Federal Court, which handed down its decision in late February following an appeal by the NDIA.
Mr Eastham's legal team argued his impairment needed only to be a cause of the need for which a support is granted, rather than the sole or most important one.
In the case, this meant it was enough that his poor vision was one of a number of reasons why he needs the scooter.
"I think it's really artificial and undignifying to try and slice people up into a bundle of diagnoses or impairments," his lawyer Mitchell Skipsey, senior solicitor at the Justice and Equity Centre told AAP.
"The court is saying recognises the fullness of a person with disabilities' life and says the NDIS needs to take into account that full picture."
Mr Eastham has not yet been given funding for the scooter and the wait continues as the agency decides whether to appeal the decision.
Mr Skipsey said it was "baffling" the agency would spent time and resources fighting a legal battle over the $7833 funding item.
The true costs of the decision could go well beyond Mr Eastham's case, however, as it potentially opens new kinds of supports for people with multiple disabilities.
"Lee's case is not an isolated one. We know of many other participants who have been similarly refused supports the law says they're entitled to," Mr Skipsey said.
"This win will force the NDIA to change its approach to funding supports for NDIS participants who face intersecting challenges."
A NDIA spokesperson told AAP that the agency is taking the necessary time to consider the Federal Court decision.
