Scleral Contact Lenses. Scleral contact lenses are a specialized type of contact lens used for managing a variety of eye conditions. They are large, and typically their diameter is 16-20mm. This is twice the size of a standard gas permeable contact lens and larger than a typical soft contact lens. Scleral contact lenses are custom made for each eye.
The loudness of sound is measured in units called decibels (dB). A decibel unit expresses the relative intensity of sounds on a scale from zero for the average least perceptible sound to about 100 dB, which is near the level most people find uncomfortably loud. Normal speech is around 50 to 60 dB. The following chart demonstrates the sound scale in decibels. When an individual is over-exposed to excessive loudness, sensitive structures of the inner ear, such as hair cells, can be damaged, causing noise-induced hearing loss (NIHL), a particular type of hearing loss.
Sound intensity, or loudness, is measured in decibels (dB). 1  A person with hearing within the normal range can hear sounds ranging from 0 to 140 dB. 2  A whisper is around 25 to 30 dB.ound intensity, or loudness, is measured in decibels (dB). 1  A person with hearing within the normal range can hear sounds ranging from 0 to 140 dB. 2  A whisper is around 25 to 30 dB.