## 1 Introduction  
A retina consists of three types of cone cells, namely L-, M-, and S-cones, which are sensitive to long, medium, and short wavelengths of visible light, respectively. The combination of responses from these three types of cone cells determines the color that is perceived. Genetic disorders can cause one or more cones to be partially or totally nonfunctional, which leads to color vision deficiency (CVD), also known as color blindness [1]. There are 250 million people affected by CVD around the world [2]. Not being able to clearly differentiate certain colors causes those with CVD to face inconveniences, misconceptions, and even dangers in their daily lives. CVD is an inborn deficiency for most of those diagnosed, and there is not yet a cure for the condition; however, contact lenses and glasses with a color filter are commercially available. By applying uniform changes to a user's field of view (FoV), these tools increase the red-green contrast but may filter out other colors. Furthermore, it is reported that wearing tinted glasses produces an uncomfortable visual experience, and these glasses may potentially impair the user's depth perception [3]. In the field of digital image processing, many methods have been proposed for supporting people with CVD. Some approaches focus on increasing the contrast for pairs of colors by modifying one or both [4; 5; 6; 7], while others use additional visual cues, such as patterns, to encode color information [8]. The Daltonization-process-based approaches improve image quality for CVD by increasing or reintroducing lost color contrasts [9; 10; 11; 12; 13]. Most of these approaches first use color deficiency simulation methods to compute the decreased or lost information. Recently, several research groups have proposed to implementing Daltonization using an optical see-through head-mounted display (OST-HMD) [12; 13]. OST-HMD provides a computational semitransparent overlay to the environment. By observing the environment through an OST-HMD, where a personal deficiency and environment adapted compensation image are displayed, a CVD user is expected to regain the lost information. However, color distortion is a problem that needs to be solved to realize the Daltonization process on OST-HMDs. Distortion happens for many reasons, such as the decay of environmental light when passing through an OST-HMD or rendering distortion [14; 15]. The most challenging problem, however, is that commercially available OST-HMDs, which are light-additive based, can only emit light that is combined with incoming light from the environment, which makes the perceived image brighter, while the Daltonization process requires some pixel values of the images be decreased. This paper proposes a novel approach for achieving arriving light control using a liquid crystal display (LCD) for realizing the Daltonization process with an OST-HMD. To validate the feasibility of the idea, a basic prototype consisting of a scene camera, a user-perspective camera, a transmissive LCD panel, and an OST-HMD was presented in [16]. Small lookup tables were used to calibrate the color distortions. The feasibility of the proposed idea was demonstrated with artificially created simple images. This paper proposes ALCC-glasses as an improved prototype system for validating and demonstrating the new arriving light chroma controllable augmented reality technology for CVD compensation. Well designed experiments were conducted to accurately predict the functions required to correct the distortions that occurred during rendering on the OST-HMD and the transmissions through the OST-HMD and the LCD. Algorithms for automatically computing the transparency of the LCD and the images being displayed on an OST-HMD are presented. Various images were used to validate the effectiveness of the proposed approach by comparing the Daltonization process results obtained with and without light subtraction. Employing an LCD for light reduction is not itself a new idea. [PERSON] et al.