It is not uncommon for schools to miss identifying dyslexia for some pupils. If they go on to further or higher education they are often instead identified at college and university. Generally, these educational establishments will arrange for a screening assessment and / or full diagnostic assessment to be carried out in order to identify the students' strengths and weaknesses and to make sure that appropriate support is provided.
Often dyslexic students are entitled to support and equipment to help with studies. The most common form of support funding is through the Disabled Students Allowance(DSA). For more information, see this link: Disabled Students Allowances (DSAs)