X As I remember, Plato spoke of the few that escaped into the bright light of day, becoming (at least temporarily) blinded. That, by itself, has a metaphorical meaning. But if the question is rhetorical, the answer is a conditional ‘Yes’ – that is, by leading the life of a philosopher (‘lover of wisdom’), i.e. following the path of philosophy. That is a lifelong process or journey, in Plato’s terms.
Y Plato mistakenly thought we could get a Truth by purely mental means and a priori principles. Not so. We have to look at, touch, feel, smell, taste and handle reality.
X Sorry to disagree. First, we don’t know what were his oral doctrines to selected disciples (the 7th letter says something in that regard, while undervaluing the written word). Second, his ontology was non-dualist rather than a scalar one: all the lower steps or stages being incorporated step-wise in the higher ones, till getting to the Good as a first principle (supreme arché) – each step or degree of being, a reflection of the one above, exactly the same as with the five koshas or sheaths of Advaita Vedanta, except that here each kosha is within the previous one and thus becoming subtler and subtler. This would result in contemplation of a unity or oneness – one reality. When Socrates spoke of Diotima, his mentor, he did so reverently, signifying or suggesting something sacred – a spiritual transmission (one might google: Plato’s secret doctrines).