Studying wood with the naked eye is called gross inspection. The next level of viewing easily available to woodworkers is with a hand lens. Sold in a range of magnifications, the best for inspecting end grain is a 10-power (10x) lens.
To make the various elements clearly visible, the end grain must be cleanly cut. I sharpened a new blade on a trim knife using an 8000 waterstone and confirmed the edge quality with the hand lens. It’s not necessary to remove a large slice of tissue since the area you will look at is less than 1/4″ x 1/4″.
What is necessary is that the blade cuts without tearing.
Consider a 10x lens a necessary member of any tool kit. Use it to inspect the cutting edges of plane blades, chisels, router bits and saw teeth, and check joint lines, surface tearout, dings and scratches.