A device has a light guide portion and a light collector portion. The light guide portion is cup shaped. The wall of the cup has a cross section defined by sections of two ellipses disposed in a predefined manner with each other. The light collector portion is also cup-shaped, inverted with reference to the light guide portion, by a section of an ellipse and straight lines defined with reference to the light guide portion. The device radiates an annular illumination at the rim of the cup through total internal reflection of light from an LED, collected by the light collector portion. The device is made of a clear, colourless, substantially transparent material by injection moulding, one example being Polycarbonate. An annular light source system and a fundus camera using such a system are also disclosed.

An image processing method performed by a processor and including detecting positions of plural vortex veins in a fundus image of an examined eye, and computing a center of distribution of the plural detected vortex vein positions.

A method of processing a sequence of images of a retina acquired by an ophthalmic device to generate retinal position tracking information indicative of retina movement during acquisition. The method includes (i) receiving one or more images of the retina; (ii) calculating a cross-correlation between a reference image and an image based on the received image(s) to acquire an offset between the image and reference image; and repeating processes (i) and (ii) to acquire, as the tracking information, respective offsets for images that are based on the respective received image(s). Another step includes modifying the reference image during the repeating, by determining a measure of similarity between correspondingly located regions of pixels in two or more received images and accentuating features in the reference image representing structures of the imaged retina in relation to other features in the reference image based on the determined measure of similarity.

A method of processing a sequence of images of a retina acquired by an ophthalmic device to generate retinal position tracking information indicative of retina movement during acquisition. The method includes (i) receiving one or more images of the retina; (ii) calculating a cross-correlation between a reference image and an image based on the received image(s) to acquire an offset between the image and reference image; and repeating processes (i) and (ii) to acquire, as the tracking information, respective offsets for images that are based on the respective received image(s). Another step includes modifying the reference image during the repeating, by determining a measure of similarity between correspondingly located regions of pixels in two or more received images and accentuating features in the reference image representing structures of the imaged retina in relation to other features in the reference image based on the determined measure of similarity.

A alteration caused in a nerve fiber layer could not accurately be displayed. There is provided a tomographic imaging apparatus including a generation means for generating a nerve fiber bundle map, a designation means for designating an arbitrary nerve fiber bundle in the nerve fiber bundle map, and a display control means for causing display means to display a parameter of the designated nerve fiber bundle.

Provided is an image processing apparatus configured to process an image of a fundus of an eye to accurately measure thicknesses of membranes that form a blood vessel wall of an eye. The image processing apparatus includes: an image acquiring unit configured to acquire an image of an eye; a vessel feature acquiring unit configured to acquire membrane candidate points that form an arbitrary wall of a blood vessel based on the acquired image; a cell identifying unit configured to identify a cell that forms the wall of the blood vessel based on the membrane candidate points; and a measuring position acquiring unit configured to identify a measuring position regarding the wall of the blood vessel based on a position of the identified cell.

Provided is an image processing apparatus configured to process an image of a fundus of an eye, which is capable of simply and accurately measuring a distribution of cells that form a blood vessel wall of an eye. The image processing apparatus includes: an image acquiring unit configured to acquire an image of an eye; a vessel feature acquiring unit configured to acquire membrane candidate points that form an arbitrary wall of a blood vessel based on the acquired image; and a cell identifying unit configured to identify a cell that forms the wall of the blood vessel based on the membrane candidate points.

A waveguide display includes a waveguide and a staircase structure coupled to the waveguide. The waveguide includes a first substrate, a second substrate, and a holographic material layer between the first substrate and the second substrate. The holographic material layer includes a first grating and a second grating. The staircase structure is positioned on top of at least a portion of the first grating but not on top of the second grating. The staircase structure includes an input grating that is on top of the first grating and is configured to couple display light into the waveguide. The first grating is configured to redirect the display light coupled into the waveguide by the input grating towards the second grating.

An instrument includes a housing with a lower hand-held portion having a user-input button and a display for displaying an MPOD score for the user. The instrument further includes a viewing tube coupled to the hand-held portion. The viewing tube terminates in an eye cup. The viewing tube is transverse to the lower hand-held portion and transmits light from a light source in a direction toward the macula. The light source is an LED and provides two colored lights alternating at an initial frequency that is not perceptible by the user. The frequency decreases from the initial frequency until the user activates the user-input button in response to a frequency at which the user perceives a flicker of the two colored lights. The frequency at the perceived flicker relates to the MPOD score of the user. The MPOD score correlates to the amount of macular pigment.

An instrument includes a housing with a lower hand-held portion having a user-input button and a display for displaying an MPOD score for the user. The instrument further includes a viewing tube coupled to the hand-held portion. The viewing tube terminates in an eye cup. The viewing tube is transverse to the lower hand-held portion and transmits light from a light source in a direction toward the macula. The light source is an LED and provides two colored lights alternating at an initial frequency that is not perceptible by the user. The frequency decreases from the initial frequency until the user activates the user-input button in response to a frequency at which the user perceives a flicker of the two colored lights. The frequency at the perceived flicker relates to the MPOD score of the user. The MPOD score correlates to the amount of macular pigment.