DX, LX, EX packages vary from generation to generation so a more specific year would allow a better answer. Generally speaking the EX got suspension, braking, and power improvements in addtion to sunroof and other interior upgrades.
some later years the difference is only marginal such as alloy wheels vs steelies.

90+ accord were all fuel injected (carbs were 89 and before)

90-95 dx models had no power windows, locks, or mirrors, no cruise control, no factory radio or speakers and no factory air conditioning(radio and a/c were added in at the dealer)
90-95 ex added sunroof and "improved fabrics" to lx interior package

90-95 ex models had 15" alloy wheels vs 14" steelies for dx, lx

90-91 ex had upgraded exhaust for 10HP over dx, lx
92-93 ex models had dual stage intake manifold and exhaust upgrade for 15HP over dx, lx
94-95 ex models added VTEC to intake side for 20HP

92+ ex models had added ABS with rear discs vs no abs/ rear drums for dx,lx

95 added V6 option with different set of upgrades