Table A2. The total trial counts and number of stimuli placed in each rating category are shown for each stimulus type (blank, weak, medium and strong) for each subject. Also shown are either the absolute or relative (blue italics) stimulus energy measurements reported as photons at the cornea. An asterisk (*) in the photons column indicates values after a correction for estimated light loss due to reflections from antireflection coated spectacle lenses (1%, subjects 2 and 4) or trial lenses (8%, subjects 3 and 5). Trials with reported ratings of ‘1’ were judged as definitely not seen and trials with reported ratings of 2 to 6 were judged to be seen with increasing confidence. In general the ratings ‘2’ and ‘3’ were used when the subject was uncertain as to whether or not the stimulus was seen and ratings of ‘4’, ‘5’, or ‘6’ reflected subjectively increasing brightness. Non-zero blank intensities are reported because the method used to control the illumination through the pinhole directed some residual light even on the darkest setting. The values reported, generally at least 2.5 log units lower that the lowest stimulus values used, are upper estimates on the maximum light at the cornea during blank presentations, the real values possibly being less due to uncertainties in accurately measuring the stimulus intensities at the lowest light levels. These non-zero blank values were used in fitting subjects' frequency of seeing curves and interpolating thresholds, but false positive rates were left uncorrected since the required correction was insignificantly small compared with the inherent uncertainty in the data.

Subject 1 - Ratings - Absolute Sensitivity, 1
Intensity	Photons	Total	1	2	3	4	5	6
Blank	5	240	75	81	59	24	1	0
Weak	210	241	38	47	63	76	17	0
Medium	251	239	20	31	43	93	40	12
Strong	292	240	10	21	23	90	66	30
Subject 1 - Ratings - Absolute Sensitivity , 2
Intensity	Photons	Total	1	2	3	4	5	6
Blank	5	241	156	71	10	3	1	0
Weak	210	239	101	48	36	34	19	1
Medium	251	240	61	34	38	73	26	8
Strong	292	240	28	14	40	61	74	23
Subject 1 - Ratings - Absolute Sensitivity , 3
Intensity	Photons	Total	1	2	3	4	5	6
Blank	5	239	167	49	21	2	0	0
Weak	210	235	62	59	46	54	13	1
Medium	251	251	44	36	46	73	45	7
Strong	292	235	9	11	28	85	80	22
Subject 1 - Ratings - Absolute Sensitivity , 4
Intensity	Photons	Total	1	2	3	4	5	6
Blank	5	365	220	42	77	26	0	0
Weak	229	362	112	29	114	104	3	0
Medium	339	364	81	24	84	149	26	0
Strong	431	369	16	5	32	182	134	0
Subject 1 - Ratings - Absolute Sensitivity , 5
Intensity	Photons	Total	1	2	3	4	5	6
Blank	5	151	108	14	24	5	0	0
Weak	229	150	84	8	43	14	1	0
Medium	364	128	36	7	27	47	11	0
Strong	477	171	23	10	37	74	27	0
Subject 1 - Ratings - Absolute Sensitivity , 6
Intensity	Photons	Total	1	2	3	4	5	6
Blank	4	179	119	40	19	1	0	0
Weak	157	197	72	33	83	8	1	0
Medium	202	159	20	12	90	34	3	0
Strong	263	185	6	4	53	109	13	0
Subject 2 - Ratings - Absolute Sensitivity
Intensity	Photons*	Total	1	2	3	4	5	6
Blank	5	136	73	36	23	4	0	0
Weak	153	139	45	27	30	35	2	0
Medium	208	157	23	14	10	72	33	5
Strong	249	134	4	5	12	53	45	15
Subject 3 - Ratings - Absolute Sensitivity
Intensity	Photons*	Total	1	2	3	4	5	6
Blank	5	207	173	17	13	4	0	0
Weak	193	193	122	26	9	26	8	2
Medium	231	208	106	15	11	36	33	7
Strong	269	192	66	17	14	38	41	16
Subject 4 - Ratings - Absolute Sensitivity
Intensity	Photons*	Total	1	2	3	4	5	6
Blank	7	203	138	40	22	3	0	0
Weak	654	203	98	51	29	20	5	0
Medium	1055	192	60	28	42	51	11	0
Strong	1344	202	15	22	38	101	26	0
Subject 5 - Ratings - Absolute Sensitivity
Intensity	Photons*	Total	1	2	3	4	5	6
Blank	10	62	58	3	0	1	0	0
Weak	276	62	15	7	6	32	2	0
Medium	402	64	9	0	6	37	12	0
Strong	503	60	0	0	2	32	26	0
Subject 1 - Ratings - Threshold Elevating Background
Intensity	Photons	Total	1	2	3	4	5	6
Blank	37	119	73	12	18	14	2	0
Weak	2393	135	34	11	24	52	14	0
Medium	3275	119	11	3	8	47	50	0
Strong	4362	127	3	1	2	27	94	0
Subject 2 - Ratings - Threshold Elevating Background
Intensity	Photons*	Total	1	2	3	4	5	6
Blank	37	179	118	28	32	1	0	0
Weak	1141	174	89	24	53	8	0	0
Medium	1727	167	33	15	90	29	0	0
Strong	2393	176	9	6	66	83	12	0