Changes

==Parietal Eye==

==Parietal Eye==

A well developed parietal "eye" (with a rudimentary lens and retina) is found in some lizards, including the green iguana, blue-tongue skink and water dragon. This sensory organ, connected to the central nervous system and the pineal gland by the small parietal nerve, functions in hormone production (including reproduction) and thermoregulation. Although sensitive to changes in light, it cannot form images. Sometimes referred to as "pineal eye" or "third eye", it it visible as an opalescent gray spot on the top of some lizard's heads.

A well developed parietal "eye" (with a rudimentary lens and retina) is found on the dorsel midline in some lizards, including the green iguana, blue-tongue skink and water dragon. This sensory organ, connected to the central nervous system and the pineal gland by the small parietal nerve, functions in hormone production (including reproduction) and thermoregulation. Although sensitive to changes in light, it cannot form images. Sometimes referred to as "pineal eye" or "third eye", it it visible as an opalescent gray spot on the top of some lizard's heads.

==Eyelids==

==Eyelids==

In some chameleon species, the eyelids have fused to produce a circular, immobile and transparent dermal aperture called a spectacle. It create an impervious barrier to topically applied medications. Lizard species lacking a spectacle have a well developed, semi-transparent, highly mobile third eyelid which is also called the 'nictitating membrane'; this membrane can close across the eye even while the eyelids remain open.

In some chameleon species, the eyelids have fused to produce a circular, immobile and transparent dermal aperture called a spectacle. It create an impervious barrier to topically applied medications. Lizard species lacking a spectacle have a well developed, semi-transparent, highly mobile third eyelid which is also called the 'nictitating membrane'; this membrane can close across the eye even while the eyelids remain open.

==The pupil==

==The pupil==

The pupil is usually round and relatively immobile in diurnal species and is usually slit-like in nocturnal species.

The pupil is usually round and relatively immobile in diurnal species and is usually slit-like in nocturnal species. Geckos, such as the Tokay gecko, have a serrated pupillary opening resembling a series of small holes when the pupil is completely closed. This specificity allows for acute vision even in dim light.

==Ophthalmologic Examination==

==Ophthalmologic Examination==