A Comparative Study of Six Methods to Measure Human Contrast Vision

UCST Studie 1 - Jämförande Studie Mellan några Befintliga Och Nyutvecklade Metoder för Att mäta Den Spektrala kontrastkänslighetsfunktionen Hos människa

This study evaluates the relative performance of different methods to measure the human spectral contrast sensitivity function (CSF).

The human spectral contrast sensitivity function (CSF) is a better way to estimate human vision than letter charts commonly used by ophthalmologists, optometrists and opticians.

The current methods used to measure the CSF are often unreliable, due to high variability between measurements. This study will compare four (4) new tests with two (2) currently used standard tests. The contrast sensitivity function will be measured using all of the six (6) methods three times (3) in each of the two (2) eyes at two (2) occasions. Each subjects CSF will be measured 6x3x2x2 = 72 times.

In addition, for each of the CSF measurements, the time used to measure the CSF and number of background variables for the subjects will be recorded.

After informed consent is obtained, the subjects will undergo a visual examination. If they match the inclusion criteria they will be included. At that time or at their earliest possible convenience, their CSF will be measured using the six methods and some background information will be recorded.

The follow-up measurement occasion will occur between 4 to 6 weeks (28 to 42 days) after the first.

To facilitate comparison with previous studies, the CSF-measurements (in rel. contrast/cycles/degree) will be converted to a log (Base 10 logarithm) scale. The unit will thus be log CSF (LCSF) [log[relative contrast]/log[cycles/per degree]].

Inclusion Criteria:

• Normal best corrected visual acuity: LogMAR = 0
• No current or previous eye disease in either eye.
• Student at Uppsala University

Exclusion Criteria:

• Previous surgery in any eye
• Inability to follow the test procedure.