|This article is about Old Snake's eyepatch in Metal Gear Solid 4. You may be looking for the cardboard 3D viewer bundled with Metal Gear Acid 2.|
The Solid Eye appeared similar to a plastic eye patch, with text of the device name and serial number printed on the front, with a small camera lens positioned below. The Solid Eye was destroyed along with Snake's OctoCamo Sneaking Suit in the microwave tunnel within Outer Haven.
The Solid Eye combined ENVG (Enhanced Night Vision Goggles) light amplification and imaging technology, and also allowed for binocular functionality (though not simultaneously). In addition, the NV capability could also reveal things that normally wouldn't be seen, such as footprints, thus allowing Snake an easier time predicting enemy route patterns and reacting accordingly.
The Solid Eye can detect in body temperature, heart rate and sweat secretion to calculate a soldier's physical and emotional state. Its camera vision utilized the fish-eye perception. Snake's model also acted as a corrective lens for far-sightedness. When heavy artillery such as tanks enter the field of view it displayed their specifications and armaments.
A similarly designed toy called Tobidacid was known to exist by Solid Snake, apparently having owned one at childhood, though Otacon was unaware of it.
- See also: Raid at World Marshal, Ambush in Africa, Abkhazian Coup, Investigation in Guadalajara, Raid in Denver, and Operation Tecumseh
|Warning: The following information is from outside Hideo Kojima's core "Metal Gear Saga." It has some level of canonicity within the continuity, but reader discretion is advised.[?]|
Raiden made use of a retractable dual Solid Eye System, which was incorporated into his headgear and worked in conjunction with his visor; the eye pieces were labeled with the text "caution /// dual solid eye system." By 2018, he had replaced the dual system with a single retractable eyepiece, labeled as an "artifical compound eye unit."
|Non-"Metal Gear Saga" information ends here.|
Behind the scenes
The name of the Solid Eye is taken directly from the Solid Eye peripheral used with Metal Gear Acid 2. Apparently, Hideo Kojima took the name from the peripheral without telling the producer of Metal Gear Acid 2, who was "surprised" when he saw it in the original TGS trailer. The name is also a play on the term "naked eye," referring to unaided human visual perception, as well as being the partial namesake of Naked Snake.
The Solid Eye's writing on the front of the eye says:
"SOLID EYE SYSTEM
OTC • 0017/02"
A similar device appears in Metal Gear Solid: Peace Walker, called the Sonic Eye, which allows Big Boss to "sense" an enemy's path and location through soundwaves. In addition, the Analyzer has features similar to that of the Solid Eye, such as analyzing soldiers and the armaments and weaknesses of vehicles, including the classification and troop strength of the latter.
Detects Everything on the Battlefield
Developed by Otacon and Sunny, Snake’s Solid Eye allows him to see, assess, & analyze nearly anything, near or far, day or night
METAL GEAR SOLID: THE LEGACY COLLECTION"
- ―Solid Eye description on Versus Battle
Dummied code in the PC version for Ground Zeroes indicated that the Solid Eye was planned to be in the game.
The Solid Eye is an equippable item for the character Gabriel Belmont in Castlevania: Lords of Shadow, which can be unlocked after beating the game.