The purpose of the human eyes is to see. Perception or depth, color differentiation, and vision are made able by the cone and rod cells found in the retina part of the organ. Research has indicated that human eyes are capable of seeing ten million different colors. When in need of good eye care, San Antonio is a recommendable location to make a visit. San Antonio eye specialists have the right experience and qualification to handle any disease that affects eyes.
Eyes are not shaped like perfect spheres, rather, they are composed of two pieces fused together. The cornea forms the frontal part. It is transparent in color and appears curved and links to the bigger part referred to as the sclera. The radius of the cornea typically measures 8 millimeters while the sclera measures 12 mm in radius. The limbus ring connects the sclera and cornea. The pupil is surrounded by the iris.
Pupil adjustment is done by two kinds of muscles in the iris called the sphincter muscle and the dilator muscle. The cornea allows external light to pass through. Light coming in through the cornea is converted into electrical signals when it falls on light sensitive cells of the retina. The retina does the conversion of light into electrical signals. Once converted into electrical signals, the optic nerve transports the signals into the brain for processing.
The eye sizes of adults have been known to vary in size from each by one or two millimeters. This observation is consistent across all ethnicities in the world over. Vertical, horizontal, and sagittal measurements vary without any observable differences based on gender and age group. Eyes grow rapidly from birth up to the age of three years. Full size is achieved at the age of thirteen years.
Eyes consist of three coats that form enclosures for three transparent structures. The outmost layer is the fibrous tunic followed by the vascular layer in the middle and lastly the retina which forms the last layer. Cornea and sclera form the fibrous tunic while vascular tunic is made of ciliary body, iris, and choroid. The layer are observed using an ophthalmoscope.
Within the named coats are flexible lens, aqueous humour, and vitreous body. The aqueous humour exists in two places, that is, the anterior chamber the posterior chamber. The location of the anterior chamber is between iris and cornea whereas the posterior chamber is placed between the iris and lens. The lens gets suspended in place by suspensory ligaments. The vitreous body is located behind lens.
Six different muscles in the eyes are responsible for movement. The muscles include medial rectus, superior rectus, inferior oblique, lateral rectus, medial rectus, and superior oblique. The muscles exert a torque on the globe resulting in pure rotation. The torque also causes translation of around a millimeter.
Eyes suffer from a large number of conditions which are caused by different causes such as disease, age, and disorder. Aging causes some changes in eyes, which result in certain medical conditions. Some conditions occur in newborns without external causes. There are many types of eye specialists including opticians, optometrists, and ophthalmologists.
Eyes are not shaped like perfect spheres, rather, they are composed of two pieces fused together. The cornea forms the frontal part. It is transparent in color and appears curved and links to the bigger part referred to as the sclera. The radius of the cornea typically measures 8 millimeters while the sclera measures 12 mm in radius. The limbus ring connects the sclera and cornea. The pupil is surrounded by the iris.
Pupil adjustment is done by two kinds of muscles in the iris called the sphincter muscle and the dilator muscle. The cornea allows external light to pass through. Light coming in through the cornea is converted into electrical signals when it falls on light sensitive cells of the retina. The retina does the conversion of light into electrical signals. Once converted into electrical signals, the optic nerve transports the signals into the brain for processing.
The eye sizes of adults have been known to vary in size from each by one or two millimeters. This observation is consistent across all ethnicities in the world over. Vertical, horizontal, and sagittal measurements vary without any observable differences based on gender and age group. Eyes grow rapidly from birth up to the age of three years. Full size is achieved at the age of thirteen years.
Eyes consist of three coats that form enclosures for three transparent structures. The outmost layer is the fibrous tunic followed by the vascular layer in the middle and lastly the retina which forms the last layer. Cornea and sclera form the fibrous tunic while vascular tunic is made of ciliary body, iris, and choroid. The layer are observed using an ophthalmoscope.
Within the named coats are flexible lens, aqueous humour, and vitreous body. The aqueous humour exists in two places, that is, the anterior chamber the posterior chamber. The location of the anterior chamber is between iris and cornea whereas the posterior chamber is placed between the iris and lens. The lens gets suspended in place by suspensory ligaments. The vitreous body is located behind lens.
Six different muscles in the eyes are responsible for movement. The muscles include medial rectus, superior rectus, inferior oblique, lateral rectus, medial rectus, and superior oblique. The muscles exert a torque on the globe resulting in pure rotation. The torque also causes translation of around a millimeter.
Eyes suffer from a large number of conditions which are caused by different causes such as disease, age, and disorder. Aging causes some changes in eyes, which result in certain medical conditions. Some conditions occur in newborns without external causes. There are many types of eye specialists including opticians, optometrists, and ophthalmologists.
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