Example of tunnel vision (bottom) The initial retinal degenerative symptoms of<unk>  are characterized by decreased night vision (nyctalopia) and the loss of the mid-peripheral visual field. The rod photoreceptor cells, which are responsible for low-light vision and are orientated mainly in the retinal periphery, are the retinal processes affected first during non-syndromic (without other conditions) forms of this disease. Visual decline progresses relatively quickly to the far peripheral field, eventually extending into the central visual field as tunnel vision increases. Visual acuity and color vision can become compromised due to accompanying loss of the cone photoreceptor cells, which are responsible for color vision, visual acuity, and sight in the central visual field. The progression of disease occurs in both eyes in a similar but not identical pattern. A variety of indirect symptoms characterize<unk>  along with the direct effects of the initial rod photoreceptor degeneration and later cone photoreceptor decline. Phenomena such as photophobia, which describes the event in which light is perceived as an intense glare, and photopsia, the presence of blinking, swirling or shimmering lights spontaneously occurring within the visual field, often manifest during the later stages of<unk> . Findings related to<unk>  have often been characterized in the fundus (back layer) of the eye as the "ophthalmic triad". This includes the development of (1) a mottled appearance of the retina and retinal pigment epithelium <unk> E) that gives the same visual appearance of Bone Spicule patterns (but are not Bone Spicules), (2) a waxy yellow appearance of the optic disk, and (3) the attenuation of blood vessels in size and Arterial/Venous ratio as they enter and exit the Optic Disk of the retina and transverse it. Non-syndromic<unk>  <unk>  appears alone without other co-morbidities) usually presents a variety of the following symptoms: * Night blindness * Tunnel vision (due to loss of peripheral vision) * Latticework vision (due to patchy loss of peripheral vision) * loss of depth perception * Photopsia (Spontaneously occurring flashes/blinking/swirling/shimmering lights) * Photophobia (aversion to bright lights) * Development of the appearance of melanin pigment in a bone spicule pattern in the fundus (not bone tissue) * Slow adjustment from dark to light environments and vice versa * Blurring of vision * Poor color separation * Loss of central vision is the last to go, because this is a disease of the rods and not the cones which are the highest in number in the Central Vision (Macula and Fovea) * Eventual blindness (legally defined as 20 degrees or less in the best seeing eye or visual acuity of 20/200 or worse. Majority of patients do not go totally Blind, they quite often retain limited non-functional vision.
Retinitis pigmentosa
Far-sightedness
Photic retinopathy
Chloroquine retinopathy
Corneal dystrophy
Sickle cell retinopathy
Ocular melanosis
Diabetic retinopathy