predominantly red–green defect
It blocks blue light and exposes the camera film only to yellow-green light from fluorescein.
<p>predominantly red–green defect</p>
<p>The property of a molecule to spontaneously emit light of a longer wavelength <strong>when stimulated </strong>by light of a shorter wavelength.</p>
The fraction of a cycle or wavelength by which one wave leads another.
The typesetters' point system.
A symbol whose identification corresponds to a certain level of visual acuity.
<p>The smallest angle of separation between two points that allows the formation of two discernible images by an optical system.</p><p>When two Airy discs are separated so that the<strong> center of one falls on the first dark ring of the other.</strong></p>
By passing white light through a blue 'excitation' filter.
They can identify letters on the '12' line from 6 m.
Electrical responses generated in the occipital cortex by visual stimulation of the eye.
A black and white square wave grating or a chequerboard pattern.
They vibrate at right angles to the direction of the wave.
A strong preference for one eye, indicated by aversive responses to occlusion, squint, nystagmus, roving gaze, and eye poking.
An offset square wave grating.
3–5 seconds of arc.
25–33 cm.
Pseudofluorescence.
1/72 inch.
It predominantly causes a blue–yellow deficit.
Because the retinal pigment epithelium does not absorb the wavelengths emitted by ICG.
They are spaced such that any light deviated by them is eliminated by destructive interference.
<p><strong>Congenital</strong> red-green defects.</p><p>They see only a random pattern of spots or incorrect numbers.</p>
6/4 acuity.
A test using pictures of objects like a cat, train, or house for visual acuity assessment.
To assess the potential visual acuity of eyes where the macula cannot be seen.
They consist of a thin layer of transparent material that causes light reflected from the superficial and deep surfaces to eliminate each other by destructive interference.
<p>Visual acuities ranging from 6/6 to 2/60 when viewed from 60 cm.</p><p>Comprises a white cylinder marked with black dots of increasing size corresponding to visual acuities</p>
Rolling ten white polystyrene spheres across a contrasting floor to assess visual tracking.
It emits yellow-green light.
The Airy disc.
<p>In a row with reference colours at each end and intervening discs in order of closest colour match.</p><p><span style="color: rgb(55, 65, 81)">84 coloured discs.</span></p>
Central, steady, and maintained fixation with either eye.
<p>Hue discrimination. only used by children</p>
Between 400 nm and 350 nm.
They produce constructive interference, resulting in a summation of the two waves.
It can cause the sensation of blue or violet colors.
H, O, T, V, and X.
Near visual acuity equivalent to 6/24 or better.
It occurs when two waves of equal amplitude are out of phase by half a cycle, canceling each other out.
4%.
Between two and five months of age.
Absorbs at 805 nm and emits at 835 nm.
Blue–yellow defects.
To photosensitise vascular lesions for diode laser photocoagulation.
Tests requiring matching should replace those based on behavioral responses.
By observing infants turning their head or eyes towards a patterned target rather than a uniform one.
Within the stroma of the cornea.
It can delineate occult choroidal neovascularisation not visible with fluorescein.
It overestimates acuity due to the moving target and short working distance.
<p>Uses colours from all parts of the spectrum which must be arranged in order from a single reference colour. </p><p>The test does not distinguish mild colour defects, but for most purposes those passing the test are unlikely to have problems with hue discrimination.</p>
