The ankh or key of life is an ancient Egyptian hieroglyphic symbol used to represent the word for life and, by extension, as a symbol of life itself.

The ankh has a T-shape topped by a droplet-shaped loop. It was used in writing as a triliteral sign, representing a sequence of three consonants, Ꜥ-n-ḫ. This sequence was found in several Egyptian words, including the terms for mirror, floral bouquet, and life. The symbol often appeared in Egyptian art as a physical object representing either life or related life-giving substances such as air or water. Commonly depicted in the hands of ancient Egyptian deities, sometimes being given by them to the pharaoh, it represents their power to sustain life and to revive human souls in the afterlife.

The ankh was a widespread decorative motif in ancient Egypt, also used decoratively by neighbouring cultures. Copts adapted it into the crux ansata, a shape with a circular rather than droplet loop, and used it as a variant of the Christian cross. The ankh came into widespread use in Western culture in the 1960s, appearing as a symbol of African cultural identity, Neopagan belief systems, and the goth subculture.The Eye of Horus, also known as left wedjat eye or udjat eye, specular to the Eye of Ra (right wedjat eye), is a concept and symbol in ancient Egyptian religion that represents well-being, healing, and protection. It derives from the mythical conflict between the god Horus with his rival Set, in which Set tore out or destroyed one or both of Horus's eyes and the eye was subsequently healed or returned to Horus with the assistance of another deity, such as Thoth. Horus subsequently offered the eye to his deceased father Osiris, and its revitalizing power sustained Osiris in the afterlife. The Eye of Horus was thus equated with funerary offerings, as well as with all the offerings given to deities in temple ritual. It could also represent other concepts, such as the moon, whose waxing and waning was likened to the injury and restoration of the eye.

The Eye of Horus symbol, a stylized eye with distinctive markings, was believed to have protective magical power and appeared frequently in ancient Egyptian art. It was one of the most common motifs for amulets, remaining in use from the Old Kingdom (c. 2686–2181 BC) to the Roman period (30 BC – 641 AD). Pairs of Horus eyes were painted on coffins during the First Intermediate Period (c. 2181–2055 BC) and Middle Kingdom (c. 2055–1650 BC). Other contexts where the symbol appeared include on carved stone stelae and on the bows of boats. To some extent the symbol was adopted by the people of regions neighboring Egypt, such as Syria, Canaan, and especially Nubia.

The eye symbol was also rendered as a hieroglyph . Egyptologists have long believed that hieroglyphs representing pieces of the symbol stand for fractions in ancient Egyptian mathematics, although this hypothesis has been challenged