Solar Eclipse

A Solar Eclipse is an event that occurs rarely in Hardmode after at least one of the Mechanical Bosses has been defeated. It is announced at the beginning of a day with the message, "A solar eclipse is happening!", and lasts from sunrise to sunset. A Solar Eclipse has a 1 in 25 (4%) chance of occurring on any particular day (for comparison, the Blood Moon has a 1 in 10 (10%) chance each night).

A Solar Eclipse is akin to a daytime Hardmode version of a Blood Moon. Enemy spawn rates are very high even near NPCs. It is different in its rarity, and in that the event takes an entire day rather than the shorter night period (15 minutes vs. the Blood Moon's 9 minutes). It also spawns more of its own unique enemies, which can each drop unique rare items: Death Sickle, Eye Spring, Broken Hero Sword, Moon Stone, and Broken Bat Wing.

Day will be only slightly brighter than at night, and the moon is visible in front of the sun.

The event only affects the surface layer, and can be avoided by burrowing well into the underground layer or below.

Strategy



 * All of these have high HP and high attack damage, some of them have special features that make fighting them extremely hard. It is recommended to treat this event as a Boss fight mixed with an Invasion, since there will be large numbers of very tough and unusually agile enemies, most of which are resistant to knockback.
 * Every enemy but the Reapers and Vampires use standard Fighter AI, (and even the same jump range as basic Zombies and Goblins) and will walk into pits just like any other zombie. Lava pit traps will destroy the whole invasion force but the reapers.  Hence, the easiest way to nullify most of the threat is to dig a simple tunnel underneath a small lava pit on some leveled terrain. That allows players to simply focus on fighting the Reapers alone, (which are rare enough that you rarely fight more than one at a time,) while collecting all the drops.
 * More advanced arenas involve putting the player in a floating room above where the Reapers can reach, with lava pits and traps set to Timers to kill off mobs, and a teleporter or two to get to loot-collection points or out of the safe room. Even without traps, a weapon that attacks through blocks (Mushroom Spear, Nettle Burst, etc.,) allows players to ignore most of the threats.
 * If the player wishes to fight the Solar Eclipse enemies directly, it is best to fight in prepared terrain. Flat terrain is good against most of the enemies, forcing them to come at only two angles, but many players recommend a pair of mounds on either side of the player to cut down on the distance at which the Eyezor can attack.
 * The enemies have a relatively large amount of health, defense, and offense, so use top-tier weapons specifically good against crowds. This basically means either high-rate-of-fire, or piercing combined with good knockback. (Eyezors don't suffer knockback, however.)  This includes weapons like the Flamethrower, Leaf Blower, Chlorophyte Shotbow, Rainbow Gun, Paladin's Hammer, among others.
 * As with most fights challenging enough for a player to want to prepare for, a Heart Statue (and Star Statue for magic-users) set to multiple timers, a Campfire, and a Heart Lantern all allow greater health regeneration. (Add a Crystal Ball as well for magic-users.)
 * Like the Blood Moon, a Water Candle and Battle Potion ups the spawn rate of enemies even higher. If you are farming enemies for the top-tier Death Sickle or Broken Hero Sword drops, these will indirectly help increase the rate of drops.
 * The high rate of enemy spawns makes getting a Biome Key Mold relatively more common. In building an arena, a player might swap out the tiles they surround themselves with in order to get a chance to spawn different molds.
 * Also using a Titan Glove will help keep the Mobs away from you, but be aware as the Vampires have insane speed and damage.
 * If you have any accessories or potions that grant the ability to walk on water, simply standing onto a large body of water (deep enough that you don't see the bottom) and using minions is an excellent way to farm and survive an eclipse.
 * Simply building a tall structure with some wooden platforms, a campfire, and a heart lantern at or near the top can be enough to keep yourself alive throughout. Factor in a Nimbus Rod or similar and you can not only survive, but farm for whatever you want or need with nigh impunity.
 * Make a deep hole about 10x10 blocks width x height. Make a small space that was presented to you in the picture above for your character about 5 blocks higher from the floor to prevent yourself from being harmed from all including the Reaper because they use the hovering AI which means just floating a few blocks above the ground and never higher or lower depending on your position.

Trivia

 * The music that plays during an eclipse is the 'Terraria 1.2 Update - Music Spoiler' that Red uploaded to his Youtube Channel 'Demilogic' (http://www.youtube.com/user/demilogic?feature=watch) on August 10, 2013.