Dr Foy stressed the Goodwin decision where the European Court of Human Rights had found that the UK had breached the rights of a transgender woman, including her right to marry.
Government recognition of LGBT rights in Ireland has expanded greatly over the past two decades.
Homosexuality was decriminalised in 1993, and most forms of discrimination based on sexual orientation are now outlawed.
He emphasised that Ireland is very much isolated within the member states of the Council of Europe with regards to these matters.
The judge concluded that by reason of the absence of any provision which would enable the acquired identity of Dr Foy to be legally recognised in this jurisdiction, the state is in breach of its positive obligations under Art 8 of the Convention.
On 6 April 2015, the Children and Family Relationships Bill 2015 was signed into law, amending (among other acts) the Adoption Act 2010, to enable same-sex couples to jointly adopt children and stepchildren.
Same-sex sexual activity was decriminalised in 1993.
In July 2010, the Oireachtas passed the Civil Partnership and Certain Rights and Obligations of Cohabitants Act 2010, recognising civil partnerships between same-sex couples.
The bill passed all stages in the lower house (Dáil), without the need for a vote, and by a margin of 48 votes to 4 in the upper house Seanad (Senate).
Foy had also issued new proceedings in 2006 relying on a new ECHR Act, which gave greater effect to the European Convention on Human Rights in Irish law.
The two cases were consolidated and were heard in April 2007.
This was the result of a campaign by Senator David Norris and the Campaign for Homosexual Law Reform which led to a ruling in 1988 that Irish laws prohibiting male homosexual activities were in contravention of the European Convention on Human Rights.