Final answer:
The most likely diagnosis is idiopathic juxtafoveal retinal telangiectasia.
Step-by-step explanation:
The most likely diagnosis based on the symptoms described would be idiopathic juxtafoveal retinal telangiectasia. This condition refers to the presence of dilated and twisted blood vessels in the retina of the eye. The opalescent retina and boxcarring of arterioles are characteristic of this condition. It is important for the student to consult a healthcare professional for a proper diagnosis and treatment.